GORF WG4600 sync issues

Winslow

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I have a GORF that was working fine for years and the video suddenly began to look blown out like the brightness was too high. It was suggested that the tube might be failing so I swapped out the monitor with another WG4600 that was confirmed working in my Defender. I can't get an image on the replacement monitor. I've also tried a GO7 with no luck.

Since dealing with this issue I've socketed and replaced the TBA530 and reflowed solder on connectors on the RGB board and the game board. The PS board has also been rebuilt and confirmed good. The game has attract sounds, coins up and plays blind.

It sure seems like a sync problem. Can someone confirm the proper connections for the video connector and sync cable (RGB, Gnd, sync) I've also tried adjusting the frequency oscillator with no improvement on the 4600.

I have a second known working board set that I can swap in to isolate if the problem is with this board set but I don't think there is a problem with it. I'm open to any suggestion you have that might help diagnose if this is a board problem or sync problem....
 
I have a GORF that was working fine for years and the video suddenly began to look blown out like the brightness was too high. It was suggested that the tube might be failing so I swapped out the monitor with another WG4600 that was confirmed working in my Defender. I can't get an image on the replacement monitor. I've also tried a GO7 with no luck.

Since dealing with this issue I've socketed and replaced the TBA530 and reflowed solder on connectors on the RGB board and the game board. The PS board has also been rebuilt and confirmed good. The game has attract sounds, coins up and plays blind.

It sure seems like a sync problem. Can someone confirm the proper connections for the video connector and sync cable (RGB, Gnd, sync) I've also tried adjusting the frequency oscillator with no improvement on the 4600.

I have a second known working board set that I can swap in to isolate if the problem is with this board set but I don't think there is a problem with it. I'm open to any suggestion you have that might help diagnose if this is a board problem or sync problem....


I would ask Buffett or mods they both have good monitor smarts.
 
I have a GORF that was working fine for years and the video suddenly began to look blown out like the brightness was too high.

Likely the "Black Level" pot on the video interface board has gone bad (high failure item).

If the monitor has never been capped, then it would be a good idea to do so.
 
Make sure the monitor you swapped in has the correct interface card, there were a bunch of different ones.
Like Ken said, that black level pot goes bad alot. Bob includes it in the cap kit. Sounds like its time for a re-cap. Dont forget the caps on the interface cards.
 
I did recap this 4600 about 6 months ago so I don't think that would fix anything. When I twist the black level pot it seems to be working and I can increase and decrease the brightness ok.

I would really like a picture or confirmation of the correct connections for RGB and GND and also where the sync wires are supposed to go. If this interface board doesn't go with this monitor then that is a problem?

I found a service bulletin from Bally/Midway that shows the video connection different from what the WG4600 manual shows. So now I'm confused on exactly where each wire goes and I've tried tons of different combinations with no video yet.
 
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36F05A16-8506-4829-AA00-D951081F8238-623-000000E43FF14407.jpg


Andrew
 
Here is how the video is looking right now.... I've tried a 2nd complete board set and having the same problems. No video - playing blind. My RGB board has a new TBA530.... Frustrating.
 

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GORF video is up and running now

Fixed it. The power supply was the problem. -5v was reading as -9.3v. This original PS PCB was rebuilt not too long ago. Put in a switcher with an AS adapter board. Video came right up. I know some purist folks don't like using switchers in place of original analog power supplies but I'm a firm believer that getting rid of these old, unreliable PS boards are the best thing for reliability. I've seen them over and over again causing problems. It sure seems that rebuilding a Defender or Joust / Robotron power supply is a waste of time. Put in a switcher and be done with RAM errors - IMO.
 
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