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Discussion Starter · #1 ·
This is my first projector. It has been operating fine during the setup. After finishing the setup and the Avia disk it shut down. What it does is cycles, starts to power up and shuts down immediatly, few seconds later same thing. to fast to get any code, I have reseated all the cards, except what I believe is the Video Out (w/heatsink). I would appreciate any ideas.
 

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Welcome Forest, This is Troy... Glad you see you made it here, but sorry you have too under these circumstances.


Did you have a chance to turn down the h width pot on the board on top?


I may have some boards to send you if you are unable to find the problem, but from what I've seen dropping in replacements seems to come with it's own set of troubles sometimes. First I have to make sure the parts I have are all good, I'd hate to send you untested parts.


This pj was shipped upside down contrary to my this side up fragile markings on the box... He had this problem, he found that flexing the case made it go away when it was on the floor, we reseated some cards and then it was fine for a while and then the problem came back.


I'm wondering if perhaps it's being flexed by the mount on the ceiling causing a bad connection again. Either that or a loose solder joint somewhere.


Any other ideas guys?


Troy
 

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forestr,


Are you seeing any picture on the tubes before it shuts down? If yes, did you happen to turn the SCREEN pots (the ones on the separate white block)? If they are too high the projector will cycle just as you describe. I had this problem a few weeks ago.


If you get no picture, do both RED LEDs go off on the H-Def board (the one that's hinged above the RED and GREEN CRTs)? If they don't both go out then you probably have a blown (shorted) Horizontal output transistor which is mounted on the heatsink near the middle (2SC4288a).
 

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Flip up the deflection board, and disconnect all the wires going to the two vertical boards between the red and green tubes. Those are the F and C boards, and fail as often as the deflection board.


Let us know, we can help!..:)


Curt
 

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Discussion Starter · #6 ·
Jerry

It doesn't stay on that long, the red led's both, flash on and off. the fans pwr on and off immediatley they don't even get up to speed.


Curt

I pulled all the connectors from F and C. problem persists

Thank You

Forestr
 

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Check that all the fans try to spin prior to shutting down. A siezed fan will cause the same thing, but should show a "EO" error code on the back.


Chip S.
 

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Forest


If you want to send it back I will fix it or replace whatever has to be replaced. I didn't really offer a warranty as you know, but I did say I would do anything and everything I can to take care of you.


Obviously that's not ideal... There would be the shipping expense and more risk of shipping damage, but that gives you an out in case you hit a brick wall or get completely fed up.


I have those boards and parts I told you about, almost a complete system but not a full working machine to test them in right now, so to send you a bunch of untested stuff and make you waste more time doesn't appeal to me, but I offer that as well if you want to try them I'll send them. I just ask that you send back what you don't need if you want to go that route.


If you aren't burned out yet, keep following the advice from the good people here and maybe that will at least narrow down the potential parts we need to look at, and the number of stuff that has to be shipped back and forth.


I wish there was a New Yorker near you that has parts and experience but I am not aware of one.


Troy


Troy
 

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Put the projector on one side and slap the bottom plate a couple of times. Sometimes, a screw wanders under the cpu cage motherboard and causes a lot of weird problems. Make SURE there is NOT a loose screw floating around in there first.

Then check all connections. You already tried the f and c drive. And both LED's on the DEF board go off? Hmmm.... measure the H-out transistor with an ohm meter anyway, if you can. You should not get a short between any of the legs. ( projector unplugged of course)

Lastly, maybe the powersupply. Do the green lights in the back stay on when it cycles?


Marc
 

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I'd say the power supply is bad. Troy have you got a spare? I'm out.


Curt
 

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Yes, I have both. Are you thinking HVPS or LVPS?


Troy
 

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forestr

have the same problem with my PG, I think its your 2SC4288A, H-out transistor, its short! I changed it now 5 times, different brands, within the TOSHIBA, but all get toasted! Checked all diodes, caps, transistors, power supply....all OK!

Last Tosiba worked for 5 minutes, I started Deflection PWB adjustments as discribed in the Service manual page 5-28. All worked fine, till 3)-3 wave generator at 55KHz want to adjust VR5007........4288A died.

I noticed it was very hot from start, like the others, but stronger, so it take 5 min to toast!

Put a new one in, and tested the Horizontal Amplitude Adjustment first, and found 2.6 V at pin 2 at connector PA!!!! 1.8V is normal, immediately I tried to adjust VR5005 H-WIDTH down to 1.8V, but turn up or down, nothing changed the 2.6V !!!!!! I switched off, not to toast the 4288A again, it was hot.


So what is wrong, I can not test all voltages on the DEF PWB like discribed in the schematics, like forestr not enough time,4288A gets hot so fast!


My question to the experts, can I pull out the DEF PWB, and test it only with the +15V, -15V and perhaps the +60V to connector PD, with my work bench power supply? Or will this kill the V-Drive output, or something else, because no yokes are connected??? Did I need the 60V for testing the H-out circuit?

I do not want connect the 36V pin1 at PA, so no trouble for 4288A !

What do you think?

Daniel
 

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Daniel,

You should test the Def board according to the schematic with a scope to see what goes on there,as Paul said use cooling spray ,and connect a multi channel scope to several test points at a time.

Again,if you have the schematic you`ll see the wave forms you should get at those locations.

Connect the scope to as many points before stating the PJ and record the waves then shut it off and take your time to figure it out .

You must run these tests while the def board is inside the projector.

If not take to a service shop,it shouldn`t be more difficult then a RPTV.


Yuval.
 

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Sounds like the H-width pot is defective or at least dirty. With the projector off, rotate the pot fully in both directions a few times and return to it's original position. Then try again.


Chip S.
 

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Paul, Yuval,

think its better to put an resistor in between choke T5001 and H-Out transistor 4288A, feed the PA1 with my own power supply, and start low with 20VDC....


Chip,

all is very clean in this machine, yes but first test was the pot, it works fine!!!!

Any more ideas, what causes the voltage not to be adjustable any more???

:confused:

Does anyone sell me an DEF PWB for the 10PG? I'm in a one way street now......the schematics are frozened in my brain....my wife gets angry too!

Please help!

Daniel
 

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Discussion Starter · #17 ·
I have tried everything suggested, I don't have the wherewithall to do anything beyond board level. I guess next step is to pull off ceiling and then decide next step. Are these close enough to RPTV for repair or try to find somebody on east coast to look at it or just send it to west coast.
 

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If you find person familiar with pg's then yes, but a general tech or rptv person n, probably a bad idea.


Let me know what happens when it's off the ceiling. If it turns out not to be caused by the ceiling mount flexing it then maybe I should just send you a power supply and a deflection board... The likely candidates.


Neither is too hard to put in. It has to come down anyway.


Troy
 
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