If you haven't noticed "Streaking" has been a hot topic around here lately. So I thought I would try a survey of other Barco owners , and maybe we can find some similarities, and finally solve this mystery.
So write down the year
model
hours
And of course if you have the streaking problem.

Example Mine is a 1995
BG808
16000 hrs

Yes I have streaking


Thanks Regards

1997 Barco Data 808s, streaks very much so

-Gary

1995 1208/2
23000 + hours
no streaking ( knock on wood )

Jonathan

Gary do you know the hours??

sorry, around 4,000

-Gary

Originally posted by Gary Murrell
1997 Barco Data 808s, streaks very much so

-Gary

Wow that is the first 808s I have heard with this problem. Guess there goes my theory of updates correcting it.

Barco 1208/2 1995 production date no streaking. Approximately 4700 hours on it before it died.

Barco 808 Data March 1996. Approximately 4170 hours, no streaking, knock on wood.

Barco 808s Data, September (I think) 1997 (for sure) Approximately 5500 hours. No streaking that I have noticed, but only put about 2-3 hours on it. Still in living room awaiting new tubes and will become my primary projector. Now that another Data 808s has been reported with the streaking issue I guess I better put some more hours on it and see.

BTW, is there some movie scene that really make this noticable so I can test for this more quickly?

uhu what exactly does streaking look like?


Fred.

It's when like you are watching the end credits for a movie. Usually it's white text on a black background.

Streaking is when the white text stretches out to the right side. Like a horonztal line that isn't supposed to be there.

Very annoying phenomenon.
Not as annoying as getting a spotburn on your blue tube as a nice surprise like I just did though...

BG 808 with 18K no streaking
BG 808 with 8K no Streaking
BD 808 with 7K no streaking

I will have to try and do better.

Pete

I'm seriously going to have to take a look.

To my knowledge, I've never seen it on the 100's of sets I've had through here.
And yes I got your email, I haven't gone through today's yet..:)

I have never seen it in the 20-30 Barcos I have seen and worked on. No where near Curt's number of course :D. However, there is a guy over on the UK version these forums who used to work for Barco who said "Barco is aware of this problem in some 808 models". It is apparently more noticeable on a very dark gray rather than perfect black background. At least the problem that "Barco was a aware of."

1208/2 1997 3500hrs no streaking

Barco Graphics 808
1997 I think
5871 hours
Yes it streaks, alot.

yes mine is only visible on gray background, not white on black credits at all

A very smart fella CRT "Henry" from the UK says it is mostly shown only on beige/gray scenes and I 100% agree

he also said that neck cards, software update and a few other things should fix the problem

-Gary

Wow were all over the place, it dosen't seem to matter the hours or the year . If its the neck cards, maybe there is some sort of difference in them because it seems age and hours has nothing to do with it .

Regards

Well the only pattern I see is that those who have seen it are all owners of Barco 808 Graphics and Data or Barco 808s Data. These all use the same rgb driver board. So unless a 120x owner or 808s Graphics owner weighs in reporting streaking (they use different boards) then that MIGHT be part of the problem, though I don't think it explains everything.

Humble 708, late 1998, ~1500 hours.

Streaks till the cows come home! :( (In the given situations ... not on credits, bright spots on black backgrounds, etc ... just bright spots on dark backgrounds)

I think a good (fairly) accessible test is the DVE disk's intro where the shuttle is entering space (ie: dark, but not black background, and bright white glow).

Just checking (very briefly) last night, and it might only be the blue tube!?! I'll try and see today whether its got a different board/chip to the other tubes (all are supposedly originals, though ... however, one of the housings/boxes on the tubes is different from the others. Cant remember if its the blue ATM).

Also possibly more noticeable on lower contrast settings!?!

Quite annoying when it causes bright streaks to flow from the nose/chin on those "artistic" shots of semi-lit faces in dark scenes! (You'd be surprised how often this shot occurs! Seems a favourite with some directors...)

Candles on any background is garenteed. You should see a scene with candles all over the room.

I know it's terrible , there has to be a cure for this . What we need is someone who has one that does streak and one that doesn't and start swapping parts until the part that cures it is found .

Regards

Tully,
I have seen this streaking on one Barco 808S B tube. As I recall it was caused by the G2/Diag board. Having seen it on other PJ's randomly over the years it is usually caused by the neck board.

Terry

A dinosaur:

1990 BG800 with 25K hours: No streaking at all. Running at 720p@71.928Hz

Note: If the MOSFET's on the neck boards of these older PJ's get old then streaking can occur.

Another FYI:

When checking for streaking you need to be really sure you're not looking at something that's actually part of the source because of a lens effect that occured at time of filming.

A good example of this is filming car headlights at night: Often you'll see the light extend to the left and right of the headlights. This is not streaking, but an artifact that occurs at time of filming.

Best to use something that you *know* isn't supposed to streak like test patterns or even end credits.

Kal

1996 Barco Data 701s 2578 hours.
1997 Barco Graphics 808s 5000 hours
with streaking:(

1995 BG 1208/2 7300 hours. No streaking.

BG808 (US version)
Nov. 1996
4000 hours
Streaking at brightness=60, no streaking (not noticeable) at 58.


Running at 1024x576@75Hz
But I don't think it's related to res/scan rate.


I strongly recommend those who reported no streaks, to look for it on gray backgrounds, whith brigtness up (and knocking on wood, of course).


I've seen it also on four or five other BG808, even with less than 2k hours on it.

I've always been interested in finding a solution.
From various subject reading (I'n not a tech guy at all) I would suspect of the VPH06 chip on the RGB amplifier.
Used also (I think) on Sony's 1992, which have been reported to suffer from streaking very often.

Originally posted by stefno
BG808 (US version)
Nov. 1996
4000 hours
Streaking at brightness=60, no streaking (not noticeable) at 58.


Now this is interesting. I was thinking that perhaps we should move beyond just age and hours. I run my Data 808 at about 55 brightness and 39-45 contrast. So that might be why some see it and others do not. I will try crank my projector up this evening and see if I can induced streaking. :D.

I run my G808 at 40 brightness usually and 45 contrast, and have streaking. True turning up the brightness makes it more obvious.

Also what resolution and refresh are folks running? 90% of my watching is 720p 60hz.

720p 48Hz for me, although I've also run 960x1440 @ 48Hz without streaking. B/C 50 / 50

Just got a new parts 1208/2 in with badly worn B and G, will check it as soon as it thaws out.

Jonathan

Just retubed a 96 BG808 (with new oem tubes) and didn't see any streaking and will be retubing another one soon, but I'm going to go back and check more throughly now just to make sure. If it is streaking, it shouldn't be too hard to find the source of it.

Originally posted by techman707
Just retubed a 96 BG808 (with new oem tubes) and didn't see any streaking and will be retubing another one soon, but I'm going to go back and check more throughly now just to make sure. If it is streaking, it shouldn't be too hard to find the source of it.

Off topic, are these the P16s you purchased a while back? Are they working well in the 808? I am waiting for some toasty tubes from Curt (I must have been one of the few folks ever to actually want toasty tubes :D) so I can transfer the hardware to make the Ampro Retro P16s suitable for my 808s Data.

Originally posted by secstate
Off topic, are these the P16s you purchased a while back? Are they working well in the 808? I am waiting for some toasty tubes from Curt (I must have been one of the few folks ever to actually want toasty tubes :D) so I can transfer the hardware to make the Ampro Retro P16s suitable for my 808s Data.

You have a PM.

I run 1440x960 at 60hz.

I have should have asked people what resolution they were running at.
I'm running 720P at 71.926 Hz .

Regards.

Hi all i had noise on my bd808s i connected a wire link from 1 of the bnc earths to the chassis earth and the noise disappeared.I have a lot of noise in my antenna system but this fixed it. Hope this helps Michael :)

Off topic,where can i find tubes for BG808s?:(

I don't think it's limited to Barco's. I have an Ampro 3300 with pretty beat tubes, I've been able to get a decent picture out of it, but at a brightness level not too much higher than my 7" 2000. Turning up the green sub con produces quite prominent streaking, noticable as an increase in red on a gray step scale, trailing the edge of any light to dark transistion. Mike Parker had a possible reason in the other streaking thread, and from what I can see on mine (haven't pulled the scope out to verify it) he is probably right.


erie

Originally posted by 701s
Off topic,where can i find tubes for BG808s?:(

If you find a source, let me know! :D

The 808 "S" uses the Sony tubes, which are non-rebuildable and with the exception of from Barco, no longer available.

Maybe i should do the MEC tube HD-144 lens mod on my BG808s.

Originally posted by 701s
Maybe i should do the MEC tube HD-144 lens mod on my BG808s.

If you can get the parts for the mod, that's one solution.;)

Major streaking here with BG808s, 1280 x 720 75hz only a few hours (all tubes perfect 10) See attached pic of green, which is worst. This makes me suspect neck board maybe?, I'm gonna have a swap round next time I get projector down.

Your getting streaking on internal text. I haven't found that with my BG808. And my tubes are not the greatest. What year is you PJ. ?

Regards

Originally posted by epatsellis
I don't think it's limited to Barco's. I have an Ampro 3300 with pretty beat tubes, I've been able to get a decent picture out of it, but at a brightness level not too much higher than my 7" 2000. Turning up the green sub con produces quite prominent streaking, noticable as an increase in red on a gray step scale, trailing the edge of any light to dark transistion. Mike Parker had a possible reason in the other streaking thread, and from what I can see on mine (haven't pulled the scope out to verify it) he is probably right.


erie




Can you give me a link to that thread Epatsellis?

Your getting streaking on internal text. I haven't found that with my BG808. And my tubes are not the greatest. What year is you PJ. ?
Tubes are mint, all perfect 10's (second set the chassis has had). Oh and that pic is directly off the tube face with lenses off, but it really does show up on the screen, drives me nuts!

Jon

Originally posted by 701s
Off topic,where can i find tubes for BG808s?:(

You can also put MEC tubes in a Graphics 808s. You need the Neckboards and the metal blocks the CRTs mount to from a MEC tubbed Barco 808.

I guess I have to try harder, but I could not get my 808 Data to streak last night. I was running my Momitsu at 720p 60hz. I cranked the contrast and bightness to no avail. I tried scenes that would like excerbate this issue as described here.

Sectstate, try an old crappy dvd. The worst I have seen is on Magnum Force, you know the old Clint Eastwood movie. The part towards the end when there on, and in, the old aircraft carrier. It's streak city! You can get this crappy dvd at Walmart for 6 bucks . To bad they don't put these good old movies on decent tranfers .

Regards

BD 808, March 1996, 20K+ hours running both 720p & 1080i, B-55, C-50.
The only time I've been able to see streaking is watching credits at the end of a movie and I had to look for it. Hasn't bothered me at all. I'll have to play with the brightness and see if that brings it out more.

Guys, if you have it, you don't need to try to find it. You will already know...
:(
Brian

BV 708 MM - 1998/4000 h - streaking :(

all three tubes , problem known by BARCO with (quite expensive) fix solution.

flo:mad:

Originally posted by usabrian
Guys, if you have it, you don't need to try to find it. You will already know...
:(
Brian

I agree except why do some have it and others don't. There must be a combination of factors that come into play. So far the 7 series and 8 series appear to suffer from it while the 120x does not, at least as reported here. But not all 8 series appear to suffer from it. I would guess at this point there is some external factors to the projector that lead to this. Perhaps the level of the signal, negative vs. positive synch, I don't know. I have seen a fair number of 808 models and have never noticed this problem. Either I am blind to it, or I have not created the right, or is that wrong, combination of factors to cause it.

I emailed Roland of B4 projection in the U.K. about the problem and this was his response.


"Hi John thanks for the Email

Unfortunately the mod I was working on was for the 708 Toshiba based tubes.

So would not be suitable for your projector.

The only modification possible would be top change the end stage over to the new style end stages as used in the Cine 8.

This would also mean a number of changes to things like the input board and power supply. By the lime you had done all that it becomes cost prohibitive at about £2000."



Sorry I can’t help further.

Roland Brooks

roland@b4projection.co.uk

0118 375 9464

Mob 07855 804 981

Interesting I am taking endstage to mean the RGB amp boards. Which is what is the greatest difference between the 808s Graphics and 120x series and the 808s that have been reported here. BTW, I still haven't been able to produce the issue on my Data 808 try as I might. I have tried three sources. I don't know if I should press my luck by trying any further :D.

Secstate, what input are you using, I'm using port 3 . And what are you using to drive your PJ. I'm using a HTPC.

Regards

Originally posted by Tully
Secstate, what input are you using, I'm using port 3 . And what are you using to drive your PJ. I'm using a HTPC.

Regards

I am using Port 5. I have a long 20 foot run of cable from closet through ceiling to projector so I have never worked out how to deal with thick coax to port 3. The sources I use on a regular basis are an HTPC and a Momitsu V880 (older version). In addition I have a Samsung NTSC HDTV box and Panasonic DVD recorder through a KeyDigital transcoder. All of these are switched through a Barco 800 switcher and then a Extron box to do the conversion to negative sync.

I only have my HTPC hooked up , and my cable is 25 feet long. I put it inside the ceiling when I built the room . It's a very good cable I had made for me . What scan rate is coming from your PC mine is 71.928hz.

Regards

I am pretty sure my HTPC scan rate is 70 Hz 1024x768. I will double check tonight. I only use my HTPC to watch downloaded TV shows from the Internet. Critical viewing of DVDs takes place on the Momitsu.

Tully I totally disagree with your opinion of "Magnum Force" the entire Dirty Harry series all 5 films were released with absolutely superb transfers and sound mixes, they are top notch DVD's

Guys i had a long discussion with Henry in the UK at crt projectors about 2 months ago, what a smart dude, i hope it is ok with him to paste what he said to me

this is called luminescence peaking and eliminated with parts from very late 1998 and later

here is the most detailed info he gave me:

**********

What you are seeing is most likely luminescence peaking, a light streak running to the right of a light object on a darker background. A dark grey rather than black background looks the worst. Early 808 suffered quite badly from this but it was fixed on later ones. The fix relates to the tube backend boards mainly and later the FET on the RGB amps. You need R7621736 RGB amps with black FET’s and the later backend boards to more or less eliminate the problem. R7621735 RGB amps with black FET’s may also reduce the problem. Parts from a late 1998 projector and up should be correct.


Be sure G2 voltages are correct, excessive voltages will make the problem worse. Only adjust with the projector fully warmed up. If the tubes are a little tired you may have to run G2 voltages up to the point were it highlights the peaking problem.



Also make sure you are running V7.31 or V7.41 software as some timing parameters were changed. Go to Service and highlight Information then press enter to check software version. V7.31 and V7.41 are identical except V7.41 is the Iris 3 upgrade. Both have the small text menus and memory bank system

*********

too me the streaking must be fixed
it is not seen all that often on my 1997 Data 808s but when the right formula pops up, it is as plain as day and right in my face

-Gary

I wonder if we could get a streaking projector to Curt or someone else who would be willing to experiment on it for the sake of the community (and thereby profit by making the same fix over and over again at a nice fee.) Hey Curt! ahem...

I know I would volunteer mine for the cause! (assuming I got it back of course)

Brian

Gary. Thanks for all that information very helpful. I have carefully adjusted my G2 so maybe that is why I am not seeing it. I don't know. I am going to upgrade the software in my Data 808s to version you mentioned. The chips can be purchased from the UK.

Gary you must have a different version than I have because I have much better DVDs. But Magnum force really does show the streaking, I find.
Also in adjusting the G2 should I be using the three pots behind the drive boards as opposed to the G2 pots right on the drive boards. And do I need a voltmeter to adjust it properly?

Regards

Sorry Gary , missed saying thanks for all that info.

Secstate, where in the UK. are you getting your stuff? I will place an order as well.

Regards

BG800

1064x764 48khz

1992 i think

don't know hours

CRT condition are 9s

I use TT1.5 for DVD, Samsung 165 OTA HD receiver

normally brightness is @ 90 in projector and contrast is 45. In TT 1.5 brightness is usually 10-20.

I just started streaking 1 month ago and I don't mean running around in public sans clothing.

Is it time to give up the 800 and go to digital? I hope not.

BG 801, nearly 42000 hours (and still running!) tubes are all in nearly pristine condition (must have been re-tubed shortly before I bought it . . .)

720p@60Hz. No streaking whatsoever.

As for source material, I imagine that the angled text scroll in the beginnning of Star Wars would be terrible.

Originally posted by Tully
Sorry Gary , missed saying thanks for all that info.

Secstate, where in the UK. are you getting your stuff? I will place an order as well.

Regards

www.crtprojectors.co.uk. I have no affiliation with the company but they do have good reputation. The upgrade was about $75.00 when I inquired about 5 months ago but is probably closer to $100 these days with the decline of the $ vs. the Pound (and everything else).

For the G2 adjustment you are supposed to use the three pots on the G2/Diagnotic board in the back of the projector with the other boards (it is the one with all the LEDs). The pots on the amp boards themselves are not part of the normal G2 adjustment.

Thanks Secstate. So can you run me through the proper way to adjust the G2 , maybe I'm doing it wrong, and it amplifies my streaking problem.

Regards

Your welcome guys, Henry who gave me that info is from crtprojectors.co.uk

-Gary

Check the H phase, adjust it up and down, its possible that its set to high or too low.

I emailed Uk projectors today and Henry told me" It’s possible that R762746 120Mhz RGB amps from MEC tubed simulation projectors might solve the problem on the Graphics 808 non “S”."
HHHMMMM may be a cure. :)

Regards

Originally posted by Tully
I emailed Uk projectors today and Henry told me" It’s possible that R762746 120Mhz RGB amps from MEC tubed simulation projectors might solve the problem on the Graphics 808 non “S”."
HHHMMMM may be a cure. :)

Regards

That would be a GREAT news!
And not only for the streaking-affected people...

I'm still waiting for Henry's reply . He's checking his stock on the amps. But this would be very good if it cured the problem.

Regards

BG808 1996

4700 hours, all tubes about 8

5m of standart grade BNC cable

neither it or I steak :-)

Bad thing is that black FET (if Henry mean VPH-06) are rare and cost very much.:( I try to find VPH-06 some time ago and those were only available from barco and cost about 200 $ each.

Red ball show VPH-06 position, in picture is old metal cover model. Newer model have black plastic cover.

Henry had the RGB amps but the cost would be about $1000 Canadian by the time I got them in from th UK. :( Maybe somone has them on this side of the big pond . Any one have any idea?

Regards

Good, Bad, I'm the guy with the gum.

http://www.*************.com/Barco/******.jpg

Remind you of anyone?

I forgot about this thread, but I finally got my G808, I think it's a 94, with 11K hours on the chassis. It has some streaking, unfortunately, which is dissappointing moving from a streak-free Marquee 8500.

I'll suck it up and live with it, not very noticeable at all in most video, however it would be something that would be nice to eliminate.

Well hopefully we all can get a handle on this streaking problem and get a fix for it , one that doesn't require us to change our projectors :( that would be a bummer.
I emailed Projection Systems to check out there stock of the RGB amps , I'm still waiting for them to get back to me . But if I can get my hands on one I will give it a try and we may have a cure. The problem is , is that these RGB amps are rare and a little pricey.

Regards

Originally posted by Z-Photo
Yikes,

It would be cheaper to buy a 1208.

Pete

Yeah but you would need a later version with MEC tubes. The earlier 1208 with MEC tubes would require some mods to the connections to take a 1208 or 1208/2 RGB amp. Also the earlier model had big black box RGB boards which I am not sure would fit in the more crowded 808. Basically you would be looking for a 1208s/2 to part out. I don't think you are likely to find the parts by themselves. You probably have to look for a parts chasis. The last one I saw with very toasty tubes went for about $1000. Of course you could sell off the other parts to make some (maybe most of) your money back. Unfortunately 1208s/2 are fairly rare and folks are willing to pay money to get the upgraded features over the earlier models.

Also one other possible source is a Barco 808 Retrographics (the rear projection version of the 808). According to the Barco CRT History spreadsheet it uses the same part number. You might be able to find one with a busted screen and worn out tubes for a fair price, but again they are fairly rare so you might be looking for a while to find one at a decent price.

Good, Bad, I'm the guy with the gum.

http://www.*************.com/Barco/******.jpg

Remind you of anyone?

Yeah just under a 1k seems to be the value of a surplus 1208s/2. They would make a very mean machine with new p16s. I may try that upgrade myself one day if I can find one for a decent price. There have been a fair number of 808 Retros these days but most have gone for more than I would have paid and one has been listed on ebay for 999.99 about 8 times. What has kept me from bidding on one is the weight and that fact that I would have to rent a truck to haul one. Only the ones minus the screen appear to go for "parts machine" prices.

Hi Secstate, your talking about the rgb amps with this part number right? R762746 . There in the Retro Graphics machines as well?

Regards

Originally posted by Tully
Hi Secstate, your talking about the rgb amps with this part number right? R762746 . There in the Retro Graphics machines as well?

Regards

Yes I am talking that part number. According to the Barco CRT History spreadsheet the Barco Retrographics 808 uses that board as well as the 1208s/2. I have never worked on a Retro 808 so cannot confirm but the Barco spreadsheets are usually accurate in my experience.

I also find it interesting that Barco chose to put a higher bandwidth RGB amp into the Retro which has a limited screen size than the front projector models (excepting the Graphics 808s).

Yes Secstate Im trying to get a hold of a few of these things so I can give it a try . They replace the neckboard and the amp as far as I know .

Regards

Originally posted by Tully
Yes Secstate Im trying to get a hold of a few of these things so I can give it a try . They replace the neckboard and the amp as far as I know .

Regards

Yep they are one piece rather than two seperate pieces in the regular 808 units. I am sure you can find some, it may just take a while.

I test once R762746 to my 801s, but unfortunately it was from retro and leaked glycol was shortened it. So I don`t know how much it helps.

R762746 have jumper that should move to other position when used instead of R762745.

Circuit board have printed instructions.

The G2 voltages will have to be recalibrated for the replacement board, each one is slightly different.

"Ile I test once R762746 to my 801s, but unfortunately it was from retro and leaked glycol was shortened it. So I don`t know how much helps.

R762746 have jumper that should move to other position when used instead of R762745.

Circuit board have printed instructions.

The G2 voltages will have to be recalibrated for the replacement board, each one is slightly different "


Thanks for the info , now all I have to do is find one .

Regards

Someone can help me with the R672757 and or R762757-5 neck board drawing? (BD 708)
Working to understand the solution BARCO implemented on these machines to avoid the streaking.


Cheers,
Flo

I'd like someone to clarify exactly what streaking or degree of streaking is being referred to here? I have now checked 2 BG-808's that I have installed new oem tubes in and completely adjusted and checked the entire projector. Neither projector has any streaking that I would call a problem or be concerned about. The ONLY way anything can be seen, and then it's very faint, is if the brightness is brought up enough to lite the entire raster well above any "normal" settings. Under those conditions, on transitions from black to white, or high contrast to low contrast, on boxes or heavy straight vertical lines, I can see the faintest ghosting or streaking.

I wish I had your problem Techman. The streaking we are talking about is when you have a lit area , say a candle , against a dark grey background, not black . The result is a streak or a tale running from the lit area off to the right side off the screen . The mouse cursor seems to do a good job of showing this as well . At the worst ,the bright areas, if they are large enough completely wash out the black on the right side of the screen .
Adjusting contrast or brightness does not have any effect. What year are your PJs ?

Regards

I have never seen it either, I guess I am lucky.... :D

Good, Bad, I'm the guy with the gum.

http://www.*************.com/Barco/******.jpg

Remind you of anyone?

808s are moded for streak free.
Changing cables/sources would not solved it.

The description Tully gave it is right, i do not know how to put pictures but i have some good exemple. It is not glowing, neither two direction candle light streak.l

I was able to reduce somehow the effect by hard disabling the ABL on my machine, but still there. Reducing G2 somehow lower the effect.

Based more on intuition and physics, i would say that this effect is due to a remanence of cathode emission excited at high level even after the signal is gone. As this effect is not seen on 600-700 lumens tubes (SD Sony series) i would say that it is linked with high brightness tubes like T180 on 70X series and similar on 80x series.(1100/1200 lumens)

If this it is true the only way to solve the problem is to kill the spot after the withe is gone, means working a solution to modify the G1 voltage based on the level of black inside the signal:mad:

Now, i am sure that the R762757 module is not fixed and the R762757-5 module has the fix for the 70x series.
A direct comparaison of these 2 drawings could clear the situation at least for the T180 tubes but also would gave some infos on the principle of solving the problem .
So anyone has the drawings?

Thanks
flo

Z-photo, Im using port three ,with a very good cable that I had made for me .

Regards

Good, Bad, I'm the guy with the gum.

http://www.*************.com/Barco/******.jpg

Remind you of anyone?

Z, if you see my photo earlier in this thread, you'll see the streaking affects even the menus, regardless of whether an input is present or not.

Jon

I only get streaking on signal sources, not on the menus, they are clear of the effect.
I have a picture of it I will try to post it later today.

Regards

Originally posted by Tully
I only get streaking on signal sources, not on the menus, they are clear of the effect.
I have a picture of it I will try to post it later today.

Regards

If you only get the "streaking" or smearing with an external signal source, why would you believe that the output amp or neck board would be involved? What I refer to above would be visible on an internally or externally generated signal.

P.S. My projectors are late 1995 units.

Techman I think maybe because the internal menus have black backgrounds and not the grey, which reveals the streaking . It's only a guess .

Regards

O yes and my BG808 is the same year as yours.

Regards

Can be found during the menu too.

But as mentioned before on totally black backgrounds the effect is less visible on the screen but should be well visible if you look inside the lens.

Tully can you check on the tube face for the menu?

flo

PS i am looking for the photos ....

BF808 63000 hours no streaking.

Daniel

Joflo , yes I will take a look into the lenses tonight when I get home , Im at work now .

Regards

Originally posted by Tully
Techman I think maybe because the internal menus have black backgrounds and not the grey, which reveals the streaking . It's only a guess .

Regards

I believe that if it's really a streaking problem, then it should definitely appear on a menu with a peak white border on a black background if you bring the brightness way up. If it doesn't appear then, I can't see it being much of an internal problem. I would be more concerned with the source and the cables if it was really noticeable.

Originally posted by Daniel Bishop
BF808 63000 hours no streaking.

Daniel

Do you mean "BG" or "BD" rather than BF?

It's a Big F'n 808.

Originally posted by Belcherwm
It's a Big F'n 808.

It sure is if it does in fact have 63000 hours on it.

Those that have the "streaking" problem, is this a "fault" or a "design flaw"? ie. Have your projectors behaved like this since day 1, or has this problem occurred over time?

I only ask because a BG808 (1996) will be coming into my posession tomorrow as a possible replacement for my 1271, but after reading this thread, perhaps the 1271 stays!

Mine's been like it since I got it over a year ago, haven't owned it from new so can't say if its been there since day 1, (I'm told it was in the board room of Rolls Royce before it came to me).

Jon

Originally posted by Telecine
Those that have the "streaking" problem, is this a "fault" or a "design flaw"? ie. Have your projectors behaved like this since day 1, or has this problem occurred over time?

I only ask because a BG808 (1996) will be coming into my posession tomorrow as a possible replacement for my 1271, but after reading this thread, perhaps the 1271 stays!

It certainly ISN'T a design flaw. Bear in mind that MOST if not all of the posters probably got their projectors after they were already used, so whether or not they had the problem from the beginning or not wouldn't having any bearing on the problem.

In my own case, I have 2 1995 units that for all practical purposes show NO streaking or smear, however, I should point out that I didn't check it prior to installing NEW oem tubes in both units.

It certainly ISN'T a design flaw. Well, I'm not convinced it isn't an inherent design flaw myself. I would say that steaking shouldn't occur over the life of the projector's chassis, tubes, etc., not just when its new. In this case, aging of the tubes, output amp, capacitors, etc. that shift the components characteristics might be a factor to consider as well as how the unit was used. The post that Barco might have an expensive fix for the problem is almost an admission of guilt on their part IMO.

Personally I haven't ever noticed this streaking. I have an 808 I'm in the process of cleaning up and maybe if it exhibits this phenomena I'll get a chance to study it a little. Another forum member that is only a few miles from me says he has streaking so maybe we can compare the machines if mine is free of the problem.

Mark

I agree with cousin.it though I haven't seen it, there is a member of the UK AV forums who used to work for Barco who said "Barco is aware of this problem." I also find it interesting that on 70x and 808 owners report it but not 120x owners or Graphic 808s owners which use different RGB boards report it. I suspect that the 808 has a tendency to do this but there are other, as yet unidentified factors, that contribute to it.

It was reported earlier in this thread that adjusting the G2 correctly would lessen the problem. I wonder how many people who are experiencing the problem have done that?

Hi Mark,
My BD 808 circa 1997 has no streaking but to get to the bottom of this issue would be great...

If EVERYONE doesn't see it, then I would think it isn't a "design" flaw. On the other hand, manufacturers buy thousands of components over the months and years of production of a model and "sometimes", they can wind up getting either a bad run of certain components, or have chosen borderline components for a particular circuit that under "certain" operating conditions may have a less than desirable life span. However, I wouldn't call that a design flaw.

Im beginning to think that this is a set up problem. Strange that two PJs of the same vintage have the problem, and not have the problem. I have to admit I'm still on the learning curve with this technology , thank goodness for this forum. So maybe it's something I'm doing ,or not doing. I just learned how to set up the power supply voltage , with the help of Curts great info page on the 808, so maybe I'm missing something else , maybe the G2 adjustment , should I be doing it with a multi meter or a scope ?
I have noticed the members with the most experience seem not to have this problem. Maybe they are doing a better setup Hmmmm.

Originally posted by Tully
Im beginning to think that this is a set up problem. Strange that two PJs of the same vintage have the problem, and not have the problem. I have to admit I'm still on the learning curve with this technology , thank goodness for this forum. So maybe it's something I'm doing ,or not doing. I just learned how to set up the power supply voltage , with the help of Curts great info page on the 808, so maybe I'm missing something else , maybe the G2 adjustment , should I be doing it with a multi meter or a scope ?
I have noticed the members with the most experience seem not to have this problem. Maybe they are doing a better setup Hmmmm.

It certainly could be the G2 adjustment, except for the fact that on a Barco, it's practically impossible to get wrong. Either the diode is OFF or it's not. There are other settings that require an extender board to set that might affect the G2 cutoff point and a few other things though.

Yes all my G2 diodes are off , but were do you adjust them from , the rgb amps were the diode is , or on the main board in the back . I put new tubes in and it was difficult to get the color balance right. Continually tinkering with the three pots on the G2 diagnostic board and then turn the pots on the rgb amps to get the diode to go out . Am I going about this the right way??

Regards

You adjust the G2 from the G2/Diagnostic board in the back NOT the RGB amp themselves. Also you have to move pot slowly. The light will only go off in one tiny area in my experience and if you move through it too fast it will not go off. Once you have tried to adjust the RGB amp pots, I believe you need a scope to get things back to normal.

Than I need a scope , so I can get things back in sinc. I wonder if this is one of my streaking problems. No where would I find the info on scoping those RGB amps ? Is it in the service manual , I don't have one of those .

Regards

Yes it is in the service manual

Unfortunately I only have the 1208 manual and it has a whole different method for adjusting the G2 so I cannot help.

Originally posted by Tully
Than I need a scope , so I can get things back in sinc. I wonder if this is one of my streaking problems. No where would I find the info on scoping those RGB amps ? Is it in the service manual , I don't have one of those .

Regards

There is a pot on the output board that ALSO affects the G2 setting, however, if you've turned that already then you need a scope to properly set that back first. There is also the video output pot on the board that requires a scope.

The G2 really shouldn't affect your overall color balance, however, it could have some affect in the color balance in the black region or on tracking.

I'm going to get a copy of the service manual , and see how I can scope it out :) . And yes, me on my learning curve turned the wrong pot. :( I will get this all set up and see if it has any effect on my streaking problem .

Regards

Just got a scope , just a 20 mhz twin trace one but it serves the needs. Took a while to remember how to use it , but I figured it out . Thanks to Javers I now have the service manual, and I set up the RGB output amps .
Wow were they out a mile , I was wondering why they were so hot . Now that I have them dialed in they run much cooler. And what a picture improvement the colors are spot on as well as the grey scale ,which was giving me so much trouble .
But the bad news is , the streaking is still there , not quite as bad, but it is still there. Now that I have the scope I'am going to read the complete manual and see if there is any thing else that needs a calibration .

Regards

Originally posted by Tully
Just got a scope , just a 20 mhz twin trace one but it serves the needs. Took a while to remember how to use it , but I figured it out . Thanks to Javers I now have the service manual, and I set up the RGB output amps .
Wow were they out a mile , I was wondering why they were so hot . Now that I have them dialed in they run much cooler. And what a picture improvement the colors are no spot on as well as the grey scale ,which was giving me so much trouble .
But the bad news is , the streaking is still there , not quite as bad, but it is still there. Now that I have the scope I'am going to read the complete manual and see if there is any thing else that needs a calibration .

Regards

If you or someone else has previously turned any of the pots, then going through the whole calibration is a good idea.

Have you noticed "any" difference with regard to the streaking issue?

P.S. Unfortunately, some of the adjustments require an extender board to get at.

The streaking is still there , but I really have to look for it. I' much happier with overall picture quality , setting up those boards really helped a lot.

Do you suggest any other adjustment Techman?

Regards

Does anyone have a scope in seattle? :)

I've been fiddling with the same pots in my barco that I goofed, trying to eyeball things and I got them very watchable, and pretty good, but things still looke a touch weird... hard to put my finger on it still. I wanna get things just so.

bump

It it very difficult to re-set the RGB amps? I can borrow a scope from work and see if I can reduce my streaking by giving them a good set up. I've only ever used a multimeter before though, never really touched a scope!

Jon

Actually remembering how to use and read a scope was the most difficult part. Once I figured that out , setting the boards only took ten minutes each. Remember you will need a two channel scope and two leads. The high voltage side of the amp is 200V , so be carefull, I got a little jolt myself. The rewards in picture quality were dramatic , but I still had some streaking. I can live with that.

Regards

I was watching the Carol Reef adventure last night , and noticed the total absence of streaking . I wonder if the streaking could be caused by the DVD software or the video card setup . WMVHD doesn't use FFDshow or any of the other software I am using except for Power Strip.
As well I don't notice any streaking on my desktop image when I am running a DVD so maybe I will try swapping the cables on the back of my PC, and driving my PJ with the one I was using to drive the PC monitor. Just a thought .


Regards

Streaking or smearing can be introduced ANYWHERE in the video chain where analog signals are concerned. If everything else is known to be good, it is usually caused by poor quality cables. If a signal can be kept in the digital domain until it is converted to analog at the projector, you are almost assured that you don't have a cable problem.

Ok here's a Kicker , Terminator two the Ultimate edition , HD disk, absolute no streaking!! I looked, and looked hard, but I couldn't see any streaking. Whats with that ??
So now I have the cure for streaking, don't watch ragular up-converted DVD's ! I thought it was something in my PJ but it must be something in the signal chain , and not my hardware . T2 was perfect even in the opening scene's with all the grays and blacks and the dude with the flashlight , no streaking !
Can't wait for September , to get my hands on a few HD DVDs .

Regards

Originally posted by Tully
Ok here's a Kicker , Terminator two the Ultimate edition , HD disk, absolute no streaking!! I looked, and looked hard, but I couldn't see any streaking. Whats with that ??
So now I have the cure for streaking, don't watch ragular up-converted DVD's ! I thought it was something in my PJ but it must be something in the signal chain , and not my hardware . T2 was perfect even in the opening scene's with all the grays and blacks and the dude with the flashlight , no streaking !
Can't wait for September , to get my hands on a few HD DVDs .

Regards

Makes sense to me, I never saw the streaking problem in the first place on 2 different units.

SO MUCH FOR BARCO STREAKING.:D

Hey Techman what is the majority of your watching , HDTV or DVD or something else?

Regards

I take Mike Parker's advice seriously, he has many times recommended the beldon 1694a cable.
My entire signal chain is nothing but Beldon 1694a, sources are all 1080i true HDTV content from D-VHS, Satellite Etc etc., occasional DVD viewing via Momitsu via 1080i

Streak's like a Sum Bitch on everything thown at it, no matter what

june 1997 Data 808s

-Gary

Hi Gary , thats so strange. I just watched Top Gun , and it streaked like a bastard to , but go to T2 HD, and smooth , no streaking . So my cables must be fine , I use port three anyway.

O yes I watched Dirty Harry again now since I redid my RGB amps and yes I agree , pretty good transfer for its age , better than Top Gun, at least my version.

Regards

If was the source or the signal chain, then ALL of us would be complaining -not just 808/1292 owners.

Those Dirty Harry's are great Tully, if you have the old Top Gun then that is crap, A new anamorphic version was just released, I have not seen it though

I have never tried port 3, I only use port 4/5

-Gary

Originally posted by Tully
Hey Techman what is the majority of your watching , HDTV or DVD or something else?

Regards

My watching is 98% DVDs. Although the picture quality on DVDs varies WIDELY, I don't think that streaking was ever a particular complaint.

Gary,

I been referring to BG-808's ONLY, as for 808 "S"'s, Graphic or Data, I wasn't aware that streaking was a big problem, but before I started to go nuts or replacing boards, I would first make sure that the projector's electronic alignment was perfect first.

Bruce

Bruce , if 98% of your viewing is DVD then what are you using as a DVD player?
Im using a HTPC with a Nvidia 5600 , Theater Tek 2 , renderles , FFD show filters and resize to 1600x1200, Lancos 4 .
But my T2 still dosen't streak at all , same with my Coral Reef Adventure . Hmmm strange .

Regards

I use an HTPC mostly, but I also use a Samsung TS-360 and Quadscan Elite HD. Although I saw no streaking on the Barcos after I retubed them and feeding them from an HTPC (ATI card) with DVDs, when I originally said there was no streaking, I was feeding test patterns from a Sencore unit.

Let me bump this up, Tech what exactly did you mean about "getting my electronic alignment perfect" I have never touched any of the service pots in my pj, or is that not what you meant

unlike the majority I have all but given up on dvd viewing, I am a D-VHS freak and have plenty of content there

I will notice a instance of streaking or it's proper term "luminance peaking" about 2 or 3 times pure movie

it never happens on black backgrounds, only on greyish brownish pics or other midtones

you will see it all the time watching concerts, like close-ups on singers their lips will streak against the backgrounds that are faintly lite from stage lights

pulling up my menus over a gray window pattern in avia shows the menus to be streaking

brightness 43 contrast 56

again thats a barco data 808s from june 1997 with 4500 hours or so

-Gary

I was referring to the service manual adjustments like Tully did.

Hum ok tech, I have never adjusted any service parameters, should they be set correctly if they have never been touched??

-Gary

Hey Gary, Mike Parker has found a cure for the streaking, if we could just get it out of him ? Look down a few threads you will see it .

Regards

great, thanks tully

-Gary

BARCO 701s ( now retired )

Streaks BLACK not WHITE form bright sharp edged images mostly text and never noticable in movies

I dont care I dotn use it any more any way
oh yea
I think 1997
701s
chasis w/ 35k hours tubes with 3000 hours

Hey anyone seen Mike Parker around here, he could solve all our problems .:D

Regards John

Three BD708 projectors, all around 3500 hours, late 1997- A lot of streaking:(
One BG808s projector,1000 hours, late 1998 - No streaking.
joflo have you find out more about the Barco mod?

Hi all!
Is streaking just behind stuff? I mean, on a white subtitle, do you get streaking to the right of the text only, or on both sides?

I have a G70 (yeah, yeah, I know, this is Barco only...) that streaks like a sonofabitch on BOTH sides of bright objects on dark background...

/ Henrik

The streaking we are talking about is prodominantly to the right of a bright image , you may have something else going on there.

Regards

Ok, just checking...

Looks like Mike Parker may have a cure for this aggravating problem we all seem to be having , all we can do is wait and see.

Regards

We installed BD808s 1997, about 4000 hours to my friend yesterday. First "streaking test" was Matrix first scene (cursor) and yes it have just same faint streaking as two of my 801s have. It can be seen easily in tube, but are visible in screen only in total darkness. Those all three have R7621735 rgb-amp's with old glossy fets.

I have been trying to find working R7621736 rgb amp (from RD808s) to test, but haven't been lucky yet. :(

Seek & thou shalt find. =)

I think I have what you need.

I've got 4 complete RD801s, 3 complete RD808s, 2 complete RG808s (without tubes) and 6 complete RD708s.

Hi there all

Never really took any notice of this thread, so here goes

Barco Data 808, July 96, 22,000 hrs, no streaking
Barco Data 701, cica 95, (cant quite remember). 1800 hrs, terrible streaking, seems to mostly come from the blue tube, when looking directly into the lenses.

Mates Barco data 808s, September 97, 18,000 hrs, streaks but very unnoticible, setup bu Roland Brooks at B4 projection.

Regards

James

HI,

Currently here
801s Data sub 3000 hrs and 801s Graphics sub 1700 hrs Both streak on credits.
using a 1280x768 75Hz pc based signal in to port 3, -ve sync pulses.

These are not my words, but well worth checking and might help the streaking issue.

Q: I have an odd horizontal line visible at times, what is it?

A: At times you may see a horizontal line that fades in the middle of the picture but it quite visible at one end (often the right side), it will be most visible on bright scenes, all white fields or light blues. This is called the horizontal line of coincidence, to some extent it's natural on some models of projector but careful adjustment can remove or at least minimise it. Pause a scene where the line is plainly visible, note which side it shows the most, go to a genlocked pattern and adjust horizontal skew to lower the horizontal centre line on the opposite side to the worst one. Do this by only a small amount, say 4-5 clicks. Now adjust top and bottom keystone to correct the error the skew change introduced. Go back to the picture, is the line less? If it's worse you skewed the wrong way, if it's better carry on tweaking the skew and keystone to minimise or remove the line. You may end up with a horizontal skew error that's plainly visible on the test pattern, it should not be obvious on actual video. Excessive use of horizontal bow may also make the line worse, again it should be possible to reduce the effect by adjusting horizontal bow and correcting the resulting top / bottom bow errors. Removing the line completely may not be possible but you should be able to reduce it to an acceptable level. The line is caused by the projector set-up making several scan line converge as they cross the tube face, result: one large visible scan line.

If deflection coil angles are set wrong or the projector is not mounted flat it will not be possible to remove the line. To check deflection coil angles check the projector is flat with a spirit level, check the screen is flat with a spirit level, sent horizontal skew to 49, delete convergence settings for that block (see this answer). Go to convergence and exactly centre red and blue on green using only the middle zone (actually raster shift). Now check the green horizontal line is parallel with the ground and that both red and blue exactly match green. If anything is wrong you have deflection coil angle problems. Correcting this will require all blocks to be deleted and the projector set to mid point in the service menu. At this point also check raster widths at approximately the scan frequency you intend to use (do this on an internal test pattern), this may save you a lot of convergence problems, including instability.

this is from henrys site, these are not my words and I am not trying to take credit for them !!!!!

As I think it true that most of us have second hand projectors with unknown pasts it is always worth checking everything you can on install (or are happy doing).

HI,

Currently here
801s Data sub 3000 hrs and 801s Graphics sub 1700 hrs Both streak on credits.
using a 1280x768 75Hz pc based signal in to port 3, -ve sync pulses.

These are not my words, but well worth checking and might help the streaking issue.

Q: I have an odd horizontal line visible at times, what is it?



That horizontal line issue is different problem and is easily solved, as you post.

We installed BD808s 1997, about 4000 hours to my friend yesterday. First "streaking test" was Matrix first scene (cursor) and yes it have just same faint streaking as two of my 801s have. It can be seen easily in tube, but are visible in screen only in total darkness. Those all three have R7621735 rgb-amp's with old glossy fets.

Being the owner of the BD 808s mentioned, I have to add a little information ;)

Manufactured in October, 1997

I had (heck, for now I still have) BG 800, which was manufactured in September, 1992 and I didn't notice streaking with it. Actually wasn't even looking for it...

Had previously a BG 500, which doesn't suffer from streaking.

We are still waiting for a Mike Parker cure , go Mike go !!


Regards

Anybody with any new ideas?

Regards

I have 2 BG-808's and NEITHER one has a streaking problem. I believe that if everything is calibrated with a scope, as per the service manual and you STILL have streaking, you need to start checking for some bad caps. I've said it before and I'll say it again now that I don't believe they designed and sold the projector NEW with a streaking problem. Just remember, you night have bought one for a $2-3K, but they originally sold for over $20K and I don't think a person buying the projector NEW would have put up with streaking.

No I would not have put up with the streaking if i had paid the new price. I have set up my RGB amps with my scope , that was a major improvement in the picture , but the streaking is still there. If some of my caps have gone dry , were would they mostly likely be? Could they be the ones on my RGB amp boards ?? If so then I will start to change them .

Regards

There are many places, power supply, neck board/RGB amps. I would say if the streaking is identical in all 3 tubes, it's a power supply problem. However, if it's different in different tubes, then the neck board/RGB amps are more likely.

The easiest way to check it is with a Secore 103 cap checker because you can do in circuit testing, otherwise an ESR meter is fine. While I've never looked into it on a Barco, on a Sony D50, when certain caps have gone bad, it allowed some power mosfet's to get damaged, which then first caused streaking, so even if you just replace the cap, you're left with the streaking. :(

The streaking seems to be the same on all three tubes, I have a couple of good RGB amps as spares, and when I put them in the streaking remains the same . Suspect the power supply, one does HMMMM . :)

Regards

The streaking seems to be the same on all three tubes, I have a couple of good RGB amps as spares, and when I put them in the streaking remains the same . Suspect the power supply, one does HMMMM . :)

Regards


Well, if it's the same on all 3 tubes and you've changed amps and it made no difference, then it can;t be in the RGB amps. It's must be in the power supply. You can probebly see poor rise and fall times. Some projectors, like the Sony G70, have peaking controls for adjusting the shape of the tube voltage waveform using the checkerboard pattern..

The rise and fall times on the power supply, or measured on the RGB amps? I have the amps set up right on spec . Using the cheakerboard pattern.
Regards

I managed to order 10 pcs newer style "black" ics (VPJ06) to rgb-amps from Korea. :) Those are already in customs of Finnland, so I should get those in few days. I hope those help something...

I let you know.

I managed to order 10 pcs newer style "black" ics (VPJ06) to rgb-amps from Korea. :) Those are already in customs of Finnland, so I should get those in few days. I hope those help something...

I let you know.

I would be very interested in your results Ile.

Regards

I too am very intersted in your results, and also where you managed to get the VPJ06 ic!

I managed to order 10 pcs newer style "black" ics (VPJ06) to rgb-amps from Korea. :) Those are already in customs of Finnland, so I should get those in few days. I hope those help something...

I let you know.
I chance one new VPJ06 in, but no big difference :(
Attachment picture is taken from tubes through lens, so problem isn't that visible in screen. Upper part is before.

At least I got one broken amp running. :)

I'm quite sure that streaking are not coming from rgb switcher, because I have three of those. No one of those aren't streaking in my BG1200.

So most probably streaking comes from driver board, have to try something in near future. I have compared schematics quickly to better one (1209s) and older driver seem to have lot of crappy bipolar capacitors that new one doesn't have...

Great work Ile, sorry to hear you haven't found a fix yet, but we all appreciate you sharing your findings! Good luck with the driver board.

Jon

I replace all el-caps to SMPS main board for other reason. No effect to streaking level.

I replace all el-caps to SMPS main board for other reason. No effect to streaking level. Nope, but at least your convergence will be super-stable now! :) (I did the same some years back in my BG800 and it did wonders for my convergence stability. Only need to tweak once every 6 months!).

Kal

I also did a few ecap replacements on the RGB input card, with no results, still streaking. Those are great pics of the streaking problem Ile. we will continue the quest for a streak free Barco . :)

Regards

Nope, but at least your convergence will be super-stable now! :)That was my main goal...

I'm also going to replace some other el-caps that have something to do with vertical and horizontal raster sift.

That should do the trick

Hey Mike P, over 5000 views on this thread . Us Barco guys are just waiting for a fix . You will have a lot of very loyal fans if you solve this one .

Regards

Does anyone have a streaking BG 808 (non s)???

and could loan/trade their SMPS for one from a non-streaking BG 808????

I have an interesting proposition for you....

Pete

Well, mine streaks when left blanking is close to the left edge of the image, but you already know that. ;)

Does anyone have a streaking BG 808 (non s)???

and could loan/trade their SMPS for one from a non-streaking BG 808????

I have an interesting proposition for you....

Pete

Hey Pete that sounds like a great Idea. how could we do this ??

Regards John

I have a couple of spare 808 SMPS (soon to be 3 more) but I do not have a streaking 808 projector.

If it is a power issue I was hoping to provide Mike Parker with both a "streaking" SMPS and a non-streaking SMPS.

PM your address and I can ship one out to you...

Pete

You got it Pete :)

Regards

Hi,

I have a BG 808 with no streaking - however when playing around with higher resolutions from the Momitsu 808DX I noted some 'black' streaking (i.e. black object surrounded by darker gray background). Because I was running over the 75 Mhz bandwidth I decided to try a lower horizontal resolution and the effect was gone.

I'm now using 1280x864 @ 50 Hz (PAL country) instead of 1440x864

Maybe this can help ...

-94 June BD801s, 11800 hours, absolutely no streaking.

BG800: 1990, 25000 hours. No streaking ever.
Zenith Pro 1200x (aka Cine8 Onyx clone): 2001, 150 hours. no streaking.

I'm surprised people are still trying to figure out why streaking happens... the reasons have been posted a couple of times now on this and another forums. Here's my cut & paste:


*******************************************
What you are seeing is most likely luminescence peaking, a light streak running to the right of a light object on a darker background. A dark grey rather than black background looks the worst. Early 808 suffered quite badly from this but it was fixed on later ones. The fix relates to the tube backend boards mainly and later the FET on the RGB amps. You need R7621736 RGB amps with black FET’s and the later backend boards to more or less eliminate the problem. R7621735 RGB amps with black FET’s may also reduce the problem. Parts from a late 1998 projector and up should be correct.
Be sure G2 voltages are correct, excessive voltages will make the problem worse. Only adjust with the projector fully warmed up. If the tubes are a little tired you may have to run G2 voltages up to the point were it highlights the peaking problem.
Also make sure you are running V7.31 or V7.41 software as some timing parameters were changed. Go to Service and highlight Information then press enter to check software version. V7.31 and V7.41 are identical except V7.41 is the Iris 3 upgrade. Both have the small text menus and memory bank system

Pasted from <http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=512219&perpage=30&highlight=808s&pagenumber=2>
*******************************************

And said slightly differently:


*******************************************
OK I think I can explain this guy's, the problem you are seeing is called luminescence peaking, this is not a problem on the Panasonic tubes but is in fact due to the RGB amps fitted to the data models.
If you notice, the BG 808s does not have this problem, but its not because of the sony tubes its the RGB amp.
The high Bandwidth amp (the integeral one with the big heat sink) is the fix, Barco went over to the Panasonic tube because its beam spot size is 15% (they used the % not I) smaller, in fact many of the simulator units and those supplied to the likes of SEOS had Panny tubes as standard.(with the High spec amp)
So in a perfect world, you need the Panasonic tube (fitted to 808s data) but with the High bandwidth RGB amp (fitted to the Graphics with sony tubes), Henry and I performed this very task for two customers on this forum,one of which is 'GODFATHER' who would no doubt like to tell of the results in his own words.(i think he's in france at the mo)
The other thing with the panny tube is because of its physical shape, you can use more tube face than the Sony tube.
Tis true barco were not aware of all of this, I can remember us having it rear its ugly head a number of years ago on some 708 visions, Barco worked closely with us on this one but to no avail, again its down to the RGB amp (back end board).
Barco went over to the Panny tube on the 'Black range' 808 so everyone automatically got the good 'cocktail version'.
Paul, not sure but thought Mike only modded the Marquee Amps (neck boards) from the earlier Marquee, up to the ultra spec neck boards however you may be correct, he could well be doing barco mods.
Remember Barco's units were not designed for home movies, it was mostly sim and presentation where that problem probably never happened.
ps paul dropped you pm recently?........
James

Pasted from <http://www.avforums.com/forums/showthread.php?p=1882773#post1882773>
*******************************************

I upgraded my R7621735 RGB amps (with black FET) to R7621736, there is only two components added. No any effect to streaking level.

I also tested my backend boards in JaniH's non streaking BD801s, no streaking.
JaniH's BD801s have older type non abl and no smd R762173 rgb amps, those use same VPH-06 chip. So problem seem to related to abl system or poorly builded smd board...

Do anybody have R762173 rgb amp schematics from Barco 801 service manual?

I'm interested about it, so I can test downgrading my rgb amps. :)

The Mike Parker Barco test mule (BG 808) will be delivered to him this Sat/Sun.

I am also providing a number of other components ( BG 808(S) RGB/CPU/Neckboard) along with the non S boards.

Maybe if people PM the heck out of him and offer to prepay for Barco fixes he will put it to the top of the list and forget about those marquees and sony things. :D

Well one can wish.

I am just glad that he is willing to take his time and look at the Barco PJs. (and the fact I have a lot of "spares")

Pete

I upgraded my R7621735 RGB amps (with black FET) to R7621736, there is only two components added. No any effect to streaking level.

I also tested my backend boards in JaniH's non streaking BD801s, no streaking.
JaniH's BD801s have older type non abl and no smd R762173 rgb amps, those use same VPH-06 chip. So problem seem to related to abl system or poorly builded smd board...

Do anybody have R762173 rgb amp schematics from Barco 801 service manual?

I'm interested about it, so I can test downgrading my rgb amps. :)

I've got the 761750 PDF if there's any interest.

The Mike Parker Barco test mule (BG 808) will be delivered to him this Sat/Sun.

I am also providing a number of other components ( BG 808(S) RGB/CPU/Neckboard) along with the non S boards.

Maybe if people PM the heck out of him and offer to prepay for Barco fixes he will put it to the top of the list and forget about those marquees and sony things. :D

Well one can wish.

I am just glad that he is willing to take his time and look at the Barco PJs. (and the fact I have a lot of "spares")

Pete

That should be very interesting. What shape are the tubes in the unit you sent to him?

The green is mint (9) the red also (8.5) the blue has some uneven wear (6-7).

Other than the new P16 and mint PT18 the second best set I got. :D

Only the best for MP...

I've got the 761750 PDF if there's any interest.
I already have 761750 pdf and it don't use VPH06 chip...

Hey Pete did you get that SMPS out to me, I can send mine right to Mike ?

Regards John

John,

No I just got back from TDY - the last few weeks have been carzy busy.

I think right now lets just wait until mike has a chance to give it the once over. I was also thinking about possible exchanging a two pice neckboard.

One thing of note

Barco Graphics 808 (non s) two piece neckboard uses VPH06
Barco retro graphics (one piece neckboard) uses VPJ08
Barco graphics 1208s/2 (one piece neckboard) uses VPH08

Not sure why the chance between the 1208 and 808

Hi Guys,

The streaking comes from the neckboards (we call em RGB amps) the 's' models should 'NOT' display this, you will find it actually occurs at a fairly limited IRE band of around 30IRE, not in a total black scene.

Its worse with say a bright object i.e a burning torch or street lamp on left side of screen and will streak accross entire screen in a narrow band.

Thus on sony tubed models 'S' derivative, it should not show because of the fitment of the high bandwidth RGB amps.

I do of course prefer the Panny tube, you can use more tube face on this and there is a trick to combine the best of both worlds, a High Bandwidth amp on a panny tube no less.....

Terry, just been to set up and calibrate a 9500 you sold to a guy in Slovenia, around 18 months+ ago do you remember it? (damn it was cold there, but oh so lovely)

James

Mine has the two piece neck board of course, have you seen any streaking on the one piece neck boards Pete.?

I wonder if you can rtrofit the two piece neckboards from a retro into a Bg 808 non s unit , HMMM do you think?

Hey how is the barkenstein working, have you got a good image on one of those yet? And of course the big question......did it streak ?

Regards John.



John,

No I just got back from TDY - the last few weeks have been carzy busy.

I think right now lets just wait until mike has a chance to give it the once over. I was also thinking about possible exchanging a two pice neckboard.

One thing of note

Barco Graphics 808 (non s) two piece neckboard uses VPH06
Barco retro graphics (one piece neckboard) uses VPJ08
Barco graphics 1208s/2 (one piece neckboard) uses VPH08

Not sure why the chance between the 1208 and 808

I have yet to get a streaking Barco. Must be the karma thing. :p

The mint P16 will be replaced by a worn PT18 due to the fact the P16 has an arc issue. :mad:

I will be sending it to VDC to get the HV lead replaced - that better solves its little arc issue or it is going to get the hammer. :eek:

Oh well - at least the LC harware on the barco LC tubes is easier to get off than the Ampro crap.

Pete

I have yet to get a streaking Barco. Must be the karma thing. :p

The mint P16 will be replaced by a worn PT18 due to the fact the P16 has an arc issue. :mad:

I will be sending it to VDC to get the HV lead replaced - that better solves its little arc issue or it is going to get the hammer. :eek:

Oh well - at least the LC harware on the barco LC tubes is easier to get off than the Ampro crap.

Pete

I've never had a streaking one either, this thread has been around a long time. :confused:

:p :D :p VDC is just the place to fix an arcing HV lead on a tube. :eek:

Bruce - I know you love their craftmanship on HV lead. :D

when in doubt add more silicone.

It almost got the hammer last night - but I counted to ten (after unplugging the PJ) and decided to give it one last chance.

Bruce - I know you love their craftmanship on HV lead. :D

when in doubt add more silicone.

It almost got the hammer last night - but I counted to ten (after unplugging the PJ) and decided to give it one last chance.

The truth is, you really need very little silicone, but, they make such a mess, you can't see what's going on. If they would use the clear protection tubing over the HV lead, there would be much less trouble. I'll bet the lead on the tube now has no protection tubing and probably has an invisible nick somewhere. I've had very good luck doing it myself, but have had a lot of problems with VDC's work.

This one actually has the clear cover - it was orginally out of a dead 3600 ampro (like there is any other kind).

The cap still looks OEM - very clean with only the bottom having the clear silicone.

It could use a longer HV wire anyway. I would do more trial and error but that was my last spare h-shift/focus board. :mad:

Pete

I would do more trial and error but that was my last spare h-shift/focus board. :mad:

Pete

Did the arcing damage other shift/focus boards? :confused:

It has toasted two shift/focus boards so far.
I have not yet checked which one went last night. I was pissed off enough already.

If it was not

1) green
2) P16
3) mint mint mint

it would already be in a million pieces.

I even sent this to tinman to check it on his sencore - all was fine internal.

Help me VDC your my only hope....
repeat

Pete

It has toasted two shift/focus boards so far.
I have not yet checked which one went last night. I was pissed off enough already.

If it was not

1) green
2) P16
3) mint mint mint

it would already be in a million pieces.

I even sent this to tinman to check it on his sencore - all was fine internal.

Help me VDC your my only hope....
repeat

Pete

Did you change the lead during any of the acring problems?

One final question: When you installed the tube in the holder, did the spring grounding fingers have good contact with the "dag" coating on the tube? If the dag isn't good or some idiot washed it off, you will never be able to stop the arcing, since it's not a HV lead problem.

The spring is in good contact - the coating is a little worn in that area (normal spring scrapes) so I added a wraparound style wire to contact with the side coating areas. with that. It could still be the coating and not the lead - at a loss at this point

If someone wants it I would be willing to swap for a another green :D

I removed one of the green PT18 from the barco LC housing so that I could give Mike a 808 with three tubes (one of each color). At least this was a little easier than the Ampro LC hardware.

Pete

edit - same OEM lead - I stink at changing them out (hack and slash).

The spring is in good contact - the coating is a little worn in that area (normal spring scrapes) so I added a wraparound style wire to contact with the side coating areas. with that. It could still be the coating and not the lead - at a loss at this point



When I think the dag might be bad, I put a strip of the copper tape that's used on the Marquee tubes. The tape and its glue have conducting properties, so I wrap it around to the good dag.

I have tested lot of things lately and most hadn't any effect to streaking level. :o

But now I finally got some results! :) Streaking in R7621735 rgb-amp seem to be caused by videopacks feedback loop. I remove that loop and chance many components related to removing. I also totally removed abl and everything related.

My test amp in red seem to work quite well after calibration. Both negative- and positive streaking have almost gone. If I look in tubes and use my imagination and worst case test method, I can barely see some streaking.

Only problem that I have found this far in quick test and calibration is that there is not enough gain control now, because feedback loop aren't boosting signal anymore. It is darn close, but I need to check if I can get +10-15 V somehow...

Need to test amp more later. Now I have to finally go to sleep, it's 02.10 here in Finland and I need to go work in the morning.

I got more adjustment to cutoff pot, but more gain seem to be harder to get. That might be the reason why they end to use that crappy feedback loop.

Funniest thing is that even modded amp have only 80 Vpp instead of 100Vpp there is no difference in contrast between modded and unmodded amps. Biggest difference between modded and unmodded amp is that modded amp (VPJ06) run much cooler.

Tested my test amp to other colours yesterday and same effect no visible streaking. :) I'm trying to do mod without removing abl and I'm going to compare those two amps.

I'm trying to do mod without removing abl and I'm going to compare those two amps.I make that kind amp and it have streaking, so it's just abl related problem.

I make two amps yesterday, where only needed abl components are removed and streaking is pretty much gone. So is my previous mod problems with too small output level. :)

Amp cutoff and gain is needed to recalibrate by scope (according to SM) after abl removing. Also G2 is needed to recalibrate by old school method, because led system is no more working. Abl is also advisable turn off from vertical deflection board switch (to ON position, Barco logic???), because abl pulses during retrace time isn't needed anymore.

Just removing abl jumper have no effect to streaking level! Video signal is still going through abl components and abl pulses are still made...

Today I'm going to make third non abl amp and going to watch some "streaky" movies. But before that I try to take some before and after pictures from tube, where mod advantage can be seen.

Awesome. Though my 808 doesn't really exhibit streaking I have been keeping my eye on this thread in case it does one day. Nice to see some progress on a streaking projector for a change :D .

Though my 808 doesn't really exhibit streaking
Are you sure you want to try my test picture? :D

Background is above video black for reason, so brightness should be first adjusted using Avia or DVE pluge pattern.

I make that kind amp and it have streaking, so it's just abl related problem.

Bingo! There is a similar evidence on Sony's AKB (same role as Barco's ABL): look at this thread: http://www.avsforum.com/avs-vb/showthread.php?t=536958&page=14&pp=30.

Now I have three amps without abl and all I can say is wow. :)
See attachment, without abl is certainly below.

Mod also help to occasionally noticeable flickering in white picture. Now black level is too low first few minutes, but that is normal for non abl projectors. In the evening I still need to recalibrate grayscale.

I can start to make instructions if somebody are interested.

ENORMOUSLY INTERESTED!!!

Thanks, Ile!!!

Congrats Ille. Very cool!

Kal

Yes very interested here too. My streaking is nothing like that but I am in the process of doing some of the cap mods that you and Z-photo pioneered and would be interested in doing this as well. I am amazed by the difference in your photos.

Interesting. I had a similar problem back when I owned a M8000. Stars in space were a dreadful "streaking" sight. KBK did some mods on my boards and that cleared up the streaking.

Nice work! The pics say it all.

Kyser

Fantastic !!! It looks like you have found a cure. We will have to move you to superstar status for your efforts. Congrates Ile.

Regards

Fantastic !!! It looks like you have found a cure. We will have to move you to superstar status for your efforts. Congrates Ile.

Regards


Agreed, many experts appear to have been stumped by this problem and you figure it out. I assuming turing off AKB means have to readjust the grayscale initially and perhaps on a more frequent periodic basis after that?

Agreed, many experts appear to have been stumped by this problem and you figure it out. I assuming turing off AKB means have to readjust the grayscale initially and perhaps on a more frequent periodic basis after that?Thanks to all for kind words.

You are right about grayscale readjustment after turning off ABL and after G2 readjustment.

I didn't notice any drift in grayscale in my previous non ABL projector over year that I used it. But I didn't have colorimeter that time...

Although the streaking on my 808 is hard to see...it's there...so I would be interested in any instructions if you are inclined to post them.

Thanks for all the hard work Ile!

I say again-you are very brave to toy with that rare VPH06............one slip of the soldering iron and its a two-eyed projector!

Highly interested in details, thanks!

-Mike

Graphics 400.

Made in: Stone age

Hours: ooooooooh lots (no hour counter)

Streaking: Nope!

- Rick

Thanks to JaniH for uploading ABL removing instructions (http://people.cc.jyu.fi/~jajuhyvo/BD801s/Removing_ABL.pdf) to his homepage.

Probably I'm going to make three more amps to my RD801s in the near future. Then I can check is gain and cut-off adjustments mandatory after abl removing. If it's not needed, it's good news to all who don't have scope.

Least I know one streaking BD808s in Finland and I can try to get my second set of amps to tested by him.

Final connection is quite near Barcos previous non abl amp 762173, so I think mod is reliable. There is some little enhancements left that I didn't want to downgrade to same as in 762173.

Considering that some have reported streaking and some have not (on the same model PJ's) is it not reasonable to assume that the streaking actually originates upstream of the ABL circuit? ABL just amplifies it? I'm thinking that removing ABL may just hide the fact that the problem actually lies elsewhere.

Any idea why ABL produces streaking?

Wow thanks for posting the details. I have an extra set of amps that I will modify.

Considering that some have reported streaking and some have not (on the same model PJ's) is it not reasonable to assume that the streaking actually originates upstream of the ABL circuit? ABL just amplifies it? I'm thinking that removing ABL may just hide the fact that the problem actually lies elsewhere.

Any idea why ABL produces streaking?
I don't know much about these things, but it's nice to speculate. :)

My guess is that ABL are not working properly in streaking sets.

I have understanded that 801/808 abl system doesn't maintain black level. In failed units bright object in the scanline somehow rise also black level (abl?) until clamp system in driver corrected it during retrace time.

120x Barcos have different kind abl system where clamp system is included, so also black level is maintained.

Any thought about my theory?

Something that I found out was that A and B ABL timing signals was just what is in schematics, but signal C (combination of A and B) is bit distorted in the end section. It doesn't have fast enough fall time, so it's not within specs. I try to correct C signal to meet the specs, but I couldn't. I scoped all my seven amps and all have same problem. I also tried another vertical deflection board.

This is really impressive, Ile! Thanks for all the hard work, and sharing your results along the way. You kind of pulled a "Thomas Edison" by carefully testing and eliminating each suspect until the culprit was found. :)

> My guess is that ABL are not working properly in streaking sets. <

As I was reading through your descriptions, I was thinking this as well. In this case, you located an inflamed appendix, and corrected the problem by surgically removing it. Yet since some sets don't exhibit the problem, their ABL circuits must be working. And for PJs that are borderline, an ABL-ectomy ;) may not be desirable.

The question would be, can the malfunction in the ABL circuit be isolated in such a way to restore proper operation, yet maintain the ABL functionality? This would make the G2's and gray scales easier to maintain, and eliminate the o'scope requirements. Plus be a lot less work to modify.

- Tim

I'll be damned :), congrats to Ile and you Barco guys :D

-Gary

Any thought about my theory?

Something that I found out was that A and B ABL timing signals was just what is in schematics, but signal C (combination of A and B) is bit distorted in the end section. It doesn't have fast enough fall time, so it's not within specs. I try to correct C signal to meet the specs, but I couldn't. I scoped all my seven amps and all have same problem. I also tried another vertical deflection board.

Sounds like a reasonable theory. But if it was ABL-specific then I would expect that RG&B would not all fail similarly. The streaking would favor one of the colors. You might see a white light streaking red or green. Streaking always seems to be white like the source...so...maybe there is something that is common that feeds all three ABL's.

My BG808 streaks just a very little on some movies. I've noticed though that sometimes the inherent video noise on dark scenes (something I have been trying to get rid of for a while) masks or mixes with streaking to make it look like the streaking is worse than it really is. But I think true streaking is minimal. If I have the time I'll put a scope on my amps and see if C is like you describe.

maybe there is something that is common that feeds all three ABL's.Vertical deflection pulses are same to all.

If I have the time I'll put a scope on my amps and see if C is like you describe.We are waiting. :D

It's definitely bad idea remove D31, D32, D33 and C41. Those components protect amp if tube short. I thought D4 would do it, but it's backwards for that purpose.

I have to update instructions.

I make mistake to look too blind to older 762173 schematic. It seem that 762173 don't have proper protection, so it might be good idea to ad something like this (http://www.avsforum.com/avs-vb/showthread.php?t=663649) to those amps.

Ile- sorry it took so long...but I found the same problem (exactly) as you. "C" is distorted and decays somewhat exponentially. I was going to draw it up but you describe it exactly. The top of the 40 us pulse 'C' was disjointed as well. It really looked like A+B plus a tail.

I've said before that I did not have streaking......well...I do. It's very slight but its there. You seem to know that the decay is beyond the specifications. I wouldn't know enough to speculate. It may be that the diagram in the schematic is just a generic picture and not the actual trace. Don't know.

I think it may be a non issue. Seems like they all do it...then again mine does have a slight streaking problem.

Hope that helps. BTW-I only checked one amp-green.

I found the same problem (exactly) as you. "C" is distorted and decays somewhat exponentially. I was going to draw it up but you describe it exactly. The top of the 40 us pulse 'C' was disjointed as well. It really looked like A+B plus a tail.I have disjointed "C" as well.

You seem to know that the decay is beyond the specifications. I wouldn't know enough to speculate. It may be that the diagram in the schematic is just a generic picture and not the actual trace. Don't know.I was just comparing my measurings to diagram, don't know either does that matter or not.

Maybe that's how it should be. :)

By the way D1 (600V) in my neckcard seem to be better tube short protection for fet than those D32 and D33 (100V) in output amp.

I have disjointed "C" as well.

I was just comparing my measurings to diagram, don't know either does that matter or not.

Maybe that's how it should be. :)
I think that is how it should be...unless someone else here scopes one that matches the graph...I noticed other little pictograms in the schematics that didn't match my scope. If the profile was really important they would probably include a photo of the trace like they do for the convergence driver board.
By the way D1 (600V) in my neckcard seem to be better tube short protection for fet than those D32 and D33 (100V) in output amp.
Why do you say that? Did you look up the specs? You didn't short something did you?

Why do you say that? Did you look up the specs? You didn't short something did you?He's referring to this post (http://www.avsforum.com/avs-vb/showthread.php?t=663649) and the previous note concerning the removal of D31, D32, D33 and C41 which should be safe afterall.

Ile-I mentioned that I have a very small amount of streaking. For reference, I have the 7621735 with the black FET's. The level of streaking is then consistent with prior posts about black FET's.

BTW-I checked G2 voltage and it was a little low but probably not enough to make any difference (1010V). Adjusting it (and redoing the G2 pots) seemed to help with brightness/contrast. Before, comfortable midtones led to darks that were too dark while brights that were too bright. After adjusting the G2 HV imaging is better. It seems I can get nice darks, good midtones while not having the brightness too high.

The last set of voltages I need to check are the preamps and the amps. Have you checked those? We spoke earlier about preamps all being 4.0 V.

Ile-I mentioned that I have a very small amount of streaking. For reference, I have the 7621735 with the black FET's. The level of streaking is then consistent with prior posts about black FET's...which FET's do you have?
Up is VPH06 and bottom is VPJ06 (black fet). (http://www.avsforum.com/avs-vb/attachment.php?attachmentid=43700) If you imagine both to same black level there is no difference in streaking level.

Amps I use now have VPJ06 and fresh elcaps.

The last set of voltages I need to check are the preamps and the amps. Have you checked those? We spoke earlier about preamps all being 4.0 V.Yes I have adjusted those driver voltages.

Have you considered what it would take to modify a 7621735 to make it a 7621736? Do you have a schematic?I have done that.

Differences are black fet and lower voltage in Q2, there is added zener and filtering cap for it. Rest differences are not in use when ICBL jumper are set for correct driver model.

Three of my late model 7621735 amps already had those zener and cap for Q2. You can check if you have those in place. I have marked positions to that instructions lay-out page by blue squares in B5.

I also tested those changes to older 7621735 that don't had those, but I couldn't see any difference.

I have schematics for 7621735, 7621736 and to previous non abl 762173 amps.

I must be misunderstanding "black FET". I thought it referred to Q33. No? Is there another FET on the output amp?

Edit: I'll check for the zener and cap...

I must be misunderstanding "black FET". I thought it referred to Q33. No? Is there another FET on the output amp?

Edit: I'll check for the zener and cap...VPJ06 is black FET (http://whatis.techtarget.com/definition/0,,sid9_gci213961,00.html)

Older VPH06 have metal case.

Thanks for clarifying. I've only heard the VPH called a video pack. Didn't realize it was really an FET.... :o but of course by definition it is.

Obviously, you now see how dangerous :eek: it is for me to be doing things like recapping and scoping....but it's the only way I can learn. I just try very hard not to get hurt or mess anything up I can't replace. I have two brother-in-laws who are EE's but of course that says nothing of my inadequacies. :D

PS-I'm not really an electrical engineer...but I play one on TV...and I did stay at a Holiday Inn Express last night!--American humor.......

Three of my late model 7621735 amps already had those zener and cap for Q2. You can check if you have those in place. I have marked positions to that instructions lay-out page by blue squares in B5.
Ile-FYI...I have the amps with the zener and cap..........late model 7621735's I guess.

Thanks for clarifying. I've only heard the VPH called a video pack. Didn't realize it was really an FET.... :o but of course by definition it is.
Yep you are right it is video pack and inside it is lot off stuff. But before in this thread it was called fet, probably because many amp use discrete components and amplifying is video packs main purpose.

Obviously, you now see how dangerous it is for me to be doing things like recapping and scoping....but it's the only way I can learn. I just try very hard not to get hurt or mess anything up I can't replace. I have two brother-in-laws who are EE's but of course that says nothing of my inadequacies.

PS-I'm not really an electrical engineer...but I play one on TV...and I did stay at a Holiday Inn Express last night!--American humor.......I'm not EE either and I haven't even been in Holiday Inn. :D

Does anyone allready applied this fix to his barco ??

I'm having the same problem with my BD808S from 1997 (8500h).

After reading thus thread i removed the ABL jumpers and when the machine is warmed up the streaks are gone.

Only problem is my barco was isf calibrated, when i remove the jumpers the calibration is gone.

The streaking may be "gone" because now the isf calibration is off. Redo the calibration and you may see it come back. For the most part, results here have been shown to be variable. The question I raised a while back is, if streaking is related to ABL then why do all three amps fail at the same time? Why doesn't streaking favor one color or the other? Removing the jumpers may mask the streaking (until you redo the isf) but I think the problem lies elsewhere.

The question I raised a while back is, if streaking is related to ABL then why do all three amps fail at the same time? Why doesn't streaking favor one color or the other? Removing the jumpers may mask the streaking (until you redo the isf) but I think the problem lies elsewhere.

This exact point was raised before (some time back) and to my knowledge has never been fully answered. May well be that modding the ABL simply masks the problem but I wonder if somewhere in amongst all the boards inside a Barco there isn't a small cap or something that no-one has ever found thats causing all the heartache :(
Paul