WG 19K7904 No display, has neck glow

CykoMF

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Donor 2011
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Machine sat unused for a couple years,
tried to fire it up the other day I get no picture.
All the other lights and stuff seem to be OK.
Drop in a credit and I can play the game blind, just no picture.

Everything is plugged in, no chewed up harness or anything.
The neck is glowing normally and I don't see anything leaking from the caps, which are most likely original. (Some still have the white glue stuff on em)


Been reading up and it sounds like this chassis had problems with bad joints or something.

Just wondered what the experts here thought I should do first.
K7000 Cap kit? Flyback?
 
Do these steps in order first:

1) Try turning up brightness to see if you get anything on the screen.

2) Try wiggling video connector to see if there is a cold solder joint there keeping the video ground from connecting.

3) Figure out how to measure the B+ and do so, then report back if it still doesn't work...
 
Do these steps in order first:

1) Try turning up brightness to see if you get anything on the screen.

2) Try wiggling video connector to see if there is a cold solder joint there keeping the video ground from connecting.

3) Figure out how to measure the B+ and do so, then report back if it still doesn't work...

1) Yes, screen turns bright gray/white with some horizontal lines on it. The lines are on a slight angle, brighter than the rest of the screen and spaced about 1.5" apart. Kind of looks like the vertical hold was out or something.

2) I had to really crank on this connector to see any change, but did manage to get the screen to turn a bit greenish, just for a brief moment though. I pulled the chassis and peeked at the video connector joints, they 'look' pretty good actually. Will touch them up anyway.

3) Just d/l'd the K7000 manual and will try to check the B+ voltage tonight. The flow chart mentions two places to check, I'll try to do both, once I find my old fluke meter.

Thanks for the assistance guys!
 
1) Yes, screen turns bright gray/white with some horizontal lines on it. The lines are on a slight angle, brighter than the rest of the screen and spaced about 1.5" apart. Kind of looks like the vertical hold was out or something.

2) I had to really crank on this connector to see any change, but did manage to get the screen to turn a bit greenish, just for a brief moment though. I pulled the chassis and peeked at the video connector joints, they 'look' pretty good actually. Will touch them up anyway.

3) Just d/l'd the K7000 manual and will try to check the B+ voltage tonight. The flow chart mentions two places to check, I'll try to do both, once I find my old fluke meter.

Thanks for the assistance guys!

1) those are raster "retrace lines". that means you went too far with the brightness. :) dial down the flyback Screen until they go away.

2) I'm told it's a common problem on the K7000s, the video header. if you have a soldering iron it's probably in your best interest to reflow all the header pins just to at least rule that out.

3) I don't know B+ on the 7000s... so good luck with that one.

I had a K7171 with gobs of solder joint problems on the neckboard. doesn't help that my neckboard has a crack running halfway through it and meeting at the neck socket. had problems with it making the heater circuit take a crap, and then I fixed it.
 
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If you have raster when you turn up the brightness, I'd say your problem lies in the video signal getting into the board. Check the connector, and trace the wires back to the game board. Also, there is a connector from the main chassis to the neckboard that might have come loose..
 
Backed off the brightness a bit and checked B+, 120V.
Followed the video harness down through a terminal block and then to the PCB. Checked of ropen circuits, all were ok.

I plugged the cable back into the PCB and when I powered the machine back up it works! Guessing it was just funky connection or something.

Man if only all repairs were that easy, thanks for the assistance guys!
 
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