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Discussion Starter · #1 ·
Just so we're all on the same page, here's the background:

DVI on Sony 2002 vs 2003
Vertical bar on Sonys when viewing 1080i
DRC modes on Sony sets
So SONY 4:3s only scan HD in their 16:9 area?


And here's the latest from the last link:
Quote:
Originally posted by montreal

Even though my question is treated in two other threads, I raised the question here because DWE referred above to a MID3 type parameter and I hoped he also knew about this mysterious MID1 DPSW parameter. Sorry to go off on a tangent.


Adu, you can only get a scrolling bar by having the incoming 1080i signal present.


My suspicion relates to what you have mentioned in your other thread about the difference between 2002 and 2003 where some circuits are bypassed for better PQ.


By chance, the solution to stopping the scrolling bar on 2002 models is also to completely bypass the circuit which up-converts 720p, and 1080i to 1080.0001i, for lack of a better name. Without the patch activated bypass circuit, I wondered if 480i and 480p were also being up-converted as well, maybe both to 1080.0001i?


The scrolling bar is due to the difference between 1080i and 1080.0001i, roughly one hertz. When bypassing the up-conversion circuit which is only reasonable for 480p and 1080i (480i and 720p both need up-conversion), you also eliminate using the two redundant a/d and d/a conversions for a better PQ.


To know that the bypass is working, one has to have over 2 volts present across pin 5/6 of connector CN3203 of the B board (TH CONTROL). This is the signal that turns on the bypass circuit. If it fails to ever turn on with the HDPT patch (I assume it always does when required), then I was wondering if the MID1 DPSW patch increased the chance that it would turn on.


This second patch (DPSW) was specified for the XBR2 but not the HS500/XBR800 and I assume that the HA3 chassis may have more privileges than the DA4 chassis since their owners paid more money for the former.


Also the TH CONTROL signal comes directly from the delicate main CPU chip outputting a MOS level signal.


In a month or two I plan on measuring the presence of my TH CONTROL signal when playing a 480p or 1080i source. I may even attach a buffered LED pilot light to come on when the signal is present.
Quote:
Originally posted by montreal

HDPT is under category OP.


As for whether 480i and 480p are up-converted to 1080i? We know that without the HDPT patch, every input signal must go through the conversion circuit.


1080i is up-converted to 1080.0001i causing the scrolling bar, and 720p is up-converted to 1080.0001i and 480i and 480p are up-converted to something.


The reason I add .0001 to the format is that we can't be sure that the horizontal frequency coming out of the converter is a precise copy or multiple of the source frequency. It is internally generated from an independent source.


So the question is if 480p goes into the up-converter, does it come out of it as 480.0001p or 960.0001i or 1080.0001i? All would look about the same because the converter does a good job. And would 480i come out of the converter as 960.0001i or 1080.0001i?


Switching on the bypass circuit for 480p and 1080i input signals allows the horizontal scanning rate to lock onto the incoming signal and completely eliminate any slow or fast scrolling vertical bar.


My guess is that all formats (480i,480p,720p, and 1080i) come out of the converter at 1080.0001i. The 1080.0001 timing is subdivided from a fixed crystal oscillator and it would be the one and only native scanning rate for the TV. You would need a oscilloscope to see it or hold a transistor AM radio near the back of the TV and tune it between stations and listen if the whining sound changes pitch when changing inputs from 1080i to 480i to 480p.


In other parts of the world, multiple formats may all get up-converted to one fixed internal clock generated scan rate as well. Perhaps in other countries the scan rates of the input signals are never very close to the TV's native scan rate so that the vertical bar scrolls too fast to be noticed.


In North America, Sony made the mistake of choosing a native scan rate too close to the up-converted scan rate ( a 1 hertz difference).
 

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Discussion Starter · #2 ·
Montreal,


If there is any unnecessary processing/conversion being applied to 1080i on the pre-2003 Sonys, I'd definitely like to try to get to the bottom of it.


I tried setting HDPT=0, and I do see a noticeable difference in the 1080i picture. I really need to get a look at a service manual, so I have a better idea what's going on in these circuits, but so far here's what I've been able to discern just playing around in the service menu.


1) With HDPT=1 (the default setting), the PQ of 1080i looks very similar to 480p and 720p, in terms of it's sharpness and saturation. However with HDPT=0, 1080i looks a bit different than the other two signals. It seems softer, less yellow, and not as saturated on my TV. Perhaps not quite as edgy or punched up.


2) Setting HDPT=0 only seems to effect 1080i on my TV. 720p & 480p look the same regardless of whether HDPT is 0 or 1.

NOTE: In Post #277 where the bar fix is mentioned, it states rather explicitely to select the RF input on some TVs before changing HDPT. So perhaps it's not such a good idea to change this item while 1080i is actually being displayed on some TVs.


3) When HDPT=1 (the default setting), changing MID1/DPSW to 0 seems to disable the video signal for 480p, 720p and 1080i, turning the screen black,(but leaving the CRT itself on).

WARNING: Changing DPSW eliminates everything from the screen, including the service menu!!! So if you push the wrong button on the remote or write changes to memory while the screen is blank, you could have a VERY difficult time getting any image back on your TV screen!!!! This stuff is for advanced service menu users only! And until more is known about this setting, I would not recommend that anyone else change it from the factory default, unless you use extreme caution and know what you're doing.


4) However, when HDPT=0, changing MID1/DPSW from 0 to 1 seems to have no effect on 1080i. IOW, the "new" 1080i picture stays on, and looks the same as far as I can tell. However, 720p, and 480p still go black as before. Again, HDPT appears to effect 1080i, but not 720p or 480p.


5) When HDPT=0, none of the MID..... sizing and positioning adjustments I've been using have any effect on the "new" 1080i picture. Like everything else though, it is resizeable with the global sizing and positioning controls in 2170D-1 (VPOS, VSIZ) & 2170D-2 (HPOS, HSIZ).


6) Unlike most service menu items, it appears that HDPT does not need to be written to memory to take effect. It seems to stay at whatever value you last entered.


7) Irrespective of any of the above, 480p does look different than the interlaced modes when viewed close up. 480p has much more distinct dots/scanlines with spaces in between than the interlaced modes. So at least in terms of what's on the screen, it appears to be scanning differently.


8) With HDPT=0, the "new" softer 1080i picture on my 34XBR800 reminds me a little bit of the softer (but perhaps more precise?) character of the image on the 34XBR910. This is probably just wishful thinking on my part though. :)


So I guess, here's my question,.... just to kind of break this down. Do you think that switching HDPT to 0 could reroute 1080i so it bypasses some of the processing or conversion that's being applied to the other signals?
 

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ADU i swear some of those posts should be required reading material.At

least for all Sony reps. Between Montreal,uzun,dt-dc, yourself and a few others the information is really invaluable. Definitely much to read but going

over it again, it starts to sink in
 

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Discussion Starter · #4 ·
:D


I was one of the unbelievers regarding the different circuitry paths. However, if there is a difference, then it would be very cool if somethin like HDPT could be used as some sort of work-around. I'm not sure we can jump to that conclusion yet though. There are still alot of unanswered questions in all this.
 

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Discussion Starter · #5 ·
Plus, we still do not know the significance of DPSW in all this.


DPSW is rather tricky BTW. If you leave it set with the picture turned off, and then press the wrong button on the remote, or write the new setting to memory you may have a heck of a time getting an image back on your TV!!!!! Because it eliminates everything from the screen, including the service menu.


So BE CAREFUL if you start playin around with this!!!!!!!!!!!!!!!


THIS STUFF IS NOT FOR THE NEWBIES.
 

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I knew there was a question that I wanted to ask, I was very tired and instead of editing or UNdoing I'll leave it.

Without reading thru the 800 line threads cause there are so many. Is there

a hardware only fix for the 1080i 2002 Sony's? I remember there being

problems not just on Sony's but the Toshiba's WS how about the Phillips , Panasonic, Samsung is any of this related? It would seem that there

were many shared boards between these Companies
 

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DPSW is rather tricky BTW. If you leave it set with the picture turned off, and then press the wrong button on the remote, or write the new setting to memory you may have a heck of a time getting an image back on your TV!!!!! Because it eliminates everything from the screen, including the service menu.


Don't tell me I am the only one with Ctrl-Alt-Del on my remote control!
 

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Discussion Starter · #8 ·
Quote:
Don't tell me I am the only one with Ctrl-Alt-Del on my remote control!
:) Yes, I guess changing to a different video input, or using the memory recall feature on the remote should "erase" the last DPSW entry and get the picture back, provided it was not accidently write it to memory. :) Is that what you're referring to? Or have you perhaps tried the "SM reset"? I don't know anyone who's tried the latter for fear of possibly undoing factory tweaks. I've been tempted to give it a go myself though.


BTW, I think the "new" 1080i wth HDPT=0 looks a bit more natural on my TV. It may be my imagination but it seems to have more subtle shades of color. And as I was saying above, it appears to eliminate some of the yellowish tint I've noticed since "correcting" the color decoders and using the Samsung 931 player, as well as reducing some edginess. Not sure if it's safe to leave HDPT at this setting though.
 

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Quote:
So I guess, here's my question,.... just to kind of break this down. Do you think that switching HDPT to 0 could reroute 1080i so it bypasses some of the processing or conversion that's being applied to the other signals?


ADU,


I'm convinced that this parameter activates the TH CONTrol signal on the 'B' board when you set it to 0. Sony claims the only way to remedy the scrolling vertical bar is to ensure that the B board contains the 2 chips that create the bypass. Some 2002 Hi Scan sets were manufactured missing these chips and these boards (series 325) are not compatible with the fix.

Series 327 boards have the chips but you also need the parameter changed to 0 to make these chips function.


As stated in the original thread on the scrolling bar, changing HDPT to 0 also changes the performance of the DC restorer circuit when viewing 1080i and this changes the brightness slightly.


The service bulletin (see original thread) tells how to correct the brightness in 1080i.


Remember that when the bypass circuit is activated, a lot of video processing is really bypassed.


I have yet to actually measure the voltage of the TH CONTrol signal to determine if the reality matches my theory. I feel very confident. Why else would Sony make a big deal about the presence of the 2 bypass chips (one for the 3 video signals and one for the 2 sync signals)?


If the bypass control signal is also being activated for 480p, then this could explain why you are getting a better PQ on 480p now that HDPT has been changed to 0.


When I do measure the control signal, then I will also test if the signal comes on for 480p. If not, I may add my own hard bypass switch to force the TH CONTrol signal to a hi state.

Quote:
5) When HDPT=0, none of the MID..... sizing and positioning adjustments I've been using have any effect on the "new" 1080i picture. Like everything else though, it is resizeable with the global sizing and positioning controls in 2170D-1 (VPOS, VSIZ) & 2170D-2 (HPOS, HSIZ).
Changing HDPT to 0 bypasses completely the DRC chip (re-scaler) and the MID chip (twin view) completely. This explains why you see no effect from changing the MID parameters. What you see on the screen is the raw 1080i signal, be it from the components input or the DVI input.
 

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Discussion Starter · #10 ·
Quote:
Changing HDPT to 0 bypasses completely the DRC chip (re-scaler) and the MID chip (twin view) completely. This explains why you see no effect from changing the MID parameters. What you see on the screen is the raw 1080i signal, be it from the components input or the DVI input.
Very interesting indeed. I'm definitely glad you brought this out.
Quote:
If the bypass control signal is also being activated for 480p, then this could explain why you are getting a better PQ on 480p now that HDPT has been changed to 0.
Actually I am (unfortunately) NOT seeing any change in 480p as a result of setting HDPT=0. It looks identical regardless of how HDPT is set. The same with 720p. Only 1080i seems to be effected by this item on my TV. I tried using some of the MID2 sizing controls on 480p after switching HDPT to 0 just to verify this, and they still work as before. So there appears to be no change to 480p.


480p does appear to scan progressively though, rather than being converted to an interlaced mode, as I mentioned above.


Perhaps there is a separate or add'l setting somewhere else which could force a 480p bypass as well.
Quote:
Remember that when the bypass circuit is activated, a lot of video processing is really bypassed.
That seems consistent with what I'm seeing on the "new" 1080i, with HDPT=0.
 

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Quote:
The 910's display format is 1080i. If you feed it with 480i, 480p, or 720p native signal, the 910 would just use the internal conversion circuitry to convert the signal to 1080i. Your 480i/480p/720p PQ is limited by the quality of the 910's format converter. In the end, it's still 1080i. And yes, I have seen slight evidence of "stairstepping" artifacts in a few HD scenes. It's very very minor. I don't think, even with progressive scan, you can completely eliminate it unless you increase the resolution to an obscene level, in the tens of thousand range.
NTN1 makes this claim in the 34XBR910 review thread. If this is true, then it means that the Hi Scan sets can only display something that's already, or converted internally to, 1080i. Without changing HDPT, even 1080i is reconverted to 1080.0001i.


If this is the case, it may be imprudent of me to attempt to force the bypass circuit to direct 480p directly to a CRT drive optimized for 1080i.


480p has a slightly slower scan rate than 1080i.


I've never understood exactly how with interlaced format, the second frame gets shifted down one extra line so that there is an interleaving of lines between the first and second frame.


I assume this is done in the studio by slightly adjusting the time delay of the first horizontal sync pulse to follow the last vertical sync pulse.

If this is the case, in theory, the Sony set should be able to display 480p directly. Perhaps linearity might suffer on a display optimized for a 1080i scan rate.
 

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Discussion Starter · #12 ·
I don't know about the 910, but NTN1's remarks re the upconversion of all signals to 1080i do not seem to jibe with what I'm seeing on my 34XBR800 screen. Again, 480p appears to scan progessively on my TV. I've been doin digital imaging alot of years, and I'm pretty sure I can distinguish the two close-up. Having one of the DVI players handy helps though, because you can easily switch between 480p and 1080i to see the difference.


However, if all you have is an analog 480i player, you can still see a difference between the interlaced and progressive modes. If you look at the screen close-up with a fairly static image, like the splash/menu screen on a DVD or the white level THX test pattern, and then switch between the different DRC de-interlacing options, you should be able to see the difference. Progressive and Cinemotion will have very distinct dots/scanlines, while the Interlaced mode will not. Interlaced will have a "smoother" appearance due to the offset of the alternating scans.
 

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Discussion Starter · #13 ·
Perahps the TV is looking at the horizontal scanrate/sync (or whatever the correct term is) to distinguish between the different incoming signals. If memory serves, 480i=15.75kHz, while 480p=31.5kHz, and 540p/1080i=33.75kHz.
 

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Discussion Starter · #14 ·
Eventually, I think the best way to handle all the different fomats on this current crop of 1080i hi-scan TVs may simply be to convert them all to 1080i via a HQ external STB and input that via DVI. The DVI players seem to demonstrate that this can be done pretty well, provided the video source is digital to begin with. If you don't have a DVI port on your TV, then going component 1080i from an external digital video hub could still be the next best thing.


I sympathize with your desire to see some more pure 480p in the meantime though. :)
 

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ADU,


I think almost all CRT HDTVs including the Sony XBR and HS are dual scan, meaning two native scan rates.


480p/960i 31.5KHz


540p/1080i 33.75KHz



So the tv is capable of natively scanning 4 types of signals although I haven't heard of 540p being used? But Sony's DRC takes advantage of the 960i capability (at least they call it an advantage)
 

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Discussion Starter · #16 ·
I think you're probably correct, xrox.


[Without the HDPT bypass] 540p from my HTPC seems to be treated just like 1080i on my TV. I.e. the alternating 540-line scans are still offset. Since the horizontal scanrates on an incoming 540p and 1080i signal are the same, perhaps the TV may have trouble distinguishing between the two, and switching the screen to progressive scan for 540p [without the HDPT bypass].


960i probably works differently though since it's generated internally by the TV's DRC functions. So as you suggest above, the TV's DRC may be able to switch the 31.5kHz signal it sends to the CRT from progressive to interlaced to deliver either 480p or 960i on the screen.


Whether the 34XBR910 works the same way though, I really don't know for sure. I haven't looked at one with the same level of scrutiny as my 34XBR800.
 

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Discussion Starter · #17 ·
I notice in Post #277 where the bar fix is mentioned, that it states very explicitely to select the RF input on the TV before changing HDPT. So perhaps it's not such a good idea to change this item while 1080i is actually being displayed on some TVs.
 

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Adu,


I agree that HDPT must be changed only when the selected input is RF (Video 1?).


When you changed DPSW, were you doing this with the input set to Video 1 (RF)?


Changing the DPSW is only required for the HA3 chassis (XBR2) and is only done along with HDPT while video5 (components) is selected. For the DA4 chassis (XBR800/HS500), only HDPT is changed and only while video1(RF) is selected.


Did you loose the on-screen display at the same time as you changed DPSW?


The on-screen display text is injected into the video path at the CRT drive circuit, after the DRC and MID.


I'm still curious as to why DPSW is changed on the KD34XBR2 but not on the XBR800.
 

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Discussion Starter · #19 ·
I'll get to your questions, montreal, but I just noticed something extremely weird today re 540p computer DVI input on my 34xbr800.


When HDPT=1, 540p scans interlaced, as though it were 1080i. No surprise there. However, when HDPT=0, 540p scans progressively! (with no jitter/flicker) on my TV, AND the signal type in the service menu is still registering as 1080i. Furthermore, DPSW does not disable the "new" progressive 540p.


So with the HDPT "bypass", these TV's seem to be smarter than I've given them credit for. I thought it would see all 33.75kHz signals the same and simply display them as interlaced 1080i. This is the way it seems to work when HDPT=1. But with HDPT=0, 540p scans progressively. So maybe the TV can sense something other than the horizontal scanrate to distinguish between an interlaced and progressive signal.... at least on a "bypassed" 33.75kHz signal.


To review:

HDPT=1

33.75kHz 1080i = interlaced scan

33.75kHz 540p = interlaced scan

And both 540p and 1080i can be disabled with DPSW=1

HDPT=0

33.75kHz 1080i = interlaced scan

33.75kHz 540p = progressive scan

And neither 540p nor 1080i can be disabled with DPSW=1


I also notice the same changes in PQ when switching HDPT from 1 to 0 with 540p as I did with 1080i. So I'm pretty sure that the HDPT "bypass" works for 540p as well, and it somehow preserves it's progressive scanning as well.


Regrettably, a 480p computer input seems to behave exactly the same as 480p from the DVD players. I.e. the HDPT "bypass" does not seem to work on it so far.
 

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Wow ... lots of good info on this thread. I've been rather busy lately and not keeping up ... looking forward to digesting some of this.
 
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