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Discussion Starter · #1 ·
I'm apparently pretty cursed with these machines. This one went for, like, 19 days... It's about like an instant replay of the last one: I came home tonight, turned it on to warm it up, about an hour later I hit standby and-- zip. Zilch. Nada. The difference between this problem and the last one is that I can clearly hear the HV "crackle" when I power it up and the last one had nothing. Everything checks out OK (CRT's are all on, PS L.E.D.'s are all on) but the tubes aren't lighting at all. No internal help screen or test patterns, either. Does anyone remember the HV code for the remote? At least if that's the problem I have another one (actually 2) to put in :) What is wrong with these damn things--- grrrrrrrr!
 

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DON`T FEEL BAD

I HAD A XG ONCE THAT HATED ME

FIRST ITS H.V.P.S. BLOWED

THEN IT SHORTED ITS BLUE TUBE

AND THEN JUST FUN IT SHORTED THE RED


XANATOS
 

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Discussion Starter · #4 ·
Quote:
Originally posted by Ray Cendroski
You might try the following thread as a place to start:

http://www.avsforum.com/avs-vb/showt...hreadid=216646


Ray
Hi Ray--


All internal settings are intact- registration, brightness, contrast, blanking, etc. When I connect or disconnect the PC you can hear the internal relay "snap" when it syncs up. My gut instinct is that it's not a CPU related thing but I could be wrong.
 

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1) Is it in 'standby' mode?

2) Did it jump memory locations and is the brightness and contrast too low (also check the blanking amounts, one might be maxed out)


3) Do a 30 code. If you get a 'system OK', then the set should be fine.



Curt
 

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Fred;


What do you see when you do a 30 code? My Ampro has the same symptoms. When I look at 30 code I get a grid 2 Lo. I'm pretty sure that my HVPS is bad although the g2 voltage is also controlled by the Vertical sweep card. Can you measure the g2 line? It is a fairly high voltage circuit( 800 to 1000 volts) so only measure with the correct tools and with caution!


Charles
 

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Discussion Starter · #7 ·
30 code- that's the one!!


Horizontal Sweep fail, Grid 2 low. Time for a HVPS swap??? I'll try to check the voltages tonight when I have some time...
 

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Fred;


The problem may not be the HVPS since you are also getting a Horizontal Sweep fail error. The problem may be elsewhere. The vertical deflection card receives both the vertical and horizontal sweep failure signals. If it receives a horizontal sweep failure signal it will cause a flip flop to change states and turn on a transistor that will cause the g2 line to go low. I'm not sure if it would still produce a grid 2 lo error in this case but maybe.


I am assuming you looked at 30 code while you had a video signal going to the projector? If this is the case I would look for the cause of the horizontal sweep failure first.


I'm pretty new at this so my views/suggestions may not be correct.


Charles
 

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Discussion Starter · #9 ·
Quote:
Originally posted by Prometheusbound
Fred;


The problem may not be the HVPS since you are also getting a Horizontal Sweep fail error. The problem may be elsewhere. The vertical deflection card receives both the vertical and horizontal sweep failure signals. If it receives a horizontal sweep failure signal it will cause a flip flop to change states and turn on a transistor that will cause the g2 line to go low. I'm not sure if it would still produce a grid 2 lo error in this case but maybe.


I am assuming you looked at 30 code while you had a video signal going to the projector? If this is the case I would look for the cause of the horizontal sweep failure first.


I'm pretty new at this so my views/suggestions may not be correct.


Charles
I did have a signal present... and like I said, there is a typical HV crackle when I power up, so what you suggest sounds logical. What should I check?? Which card is the VD card- I may have another here I can swap from another unit (a 1500) but I don't know if they use the same card or not. I'm going to look at them in a bit.
 

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I believe Charles is correct about the "G2 fault" actually being generated by the Horizontal Sweep failure". I was told this by an Ampro factory rep just before they went under. Apparently this was a well known quirk to them.


In my case I truely had no horizontal sweep (as well as the G2 fault) so I only had vertical lines down the center of the crt's. You might check the HOT (large board mtd on right wall of projector) to see if the fuse in the upper right corner is ok. You might also check the Switch Mode Power Supply to see if it is feeding 190 volts to that fuse.


I seem to remember getting diagnostics like that in the past when the projector wasn't receiving a proper video signal.


Ray
 

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Discussion Starter · #11 ·
Yep- the fuse was blown. I intelligently put the one from the other unit in, blew it and THEN checked the voltage. It reads 250v across the actual fuse (with it out, of course.) Now I need to get more fuses- any idea what value it is?? I might have a schematic on that board but it's really hard to access.... hey Curt.... :D
 
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