burgertime lines on screen

BubbaK

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I just recapped the sound board section on burgertime.. I replaced all the caps, and the 2 555 timers and the 4558C chip. I replaced the original MC4558C with a MC4558CN chip.. didn't think it would matter, but couldn't find the chip without the N. The sound is great, however I now have video issue. The HS screen and info screen display fine, but the game boards have a bunch of white lines through the screen now. I wouldn't expect what I did to be related, but never seen the lines before. I've pulled the boards, pressed on all the socketed chips, checked the ribbon cables, and gone over my work. What am I missing?

2012-03-24_18-15-20_177.jpg


2012-03-24_18-14-55_222.jpg
 
I've had the exact same symptom with my BT, and I'm nearly certain it's the ribbon cable that connects the 2 logic boards together. I've fiddled with mine and the problem is gone for now, but replacing that cable is on my short list.
 
I will check them again. I did find a few weak solder joints that I repaired in some. I'll look at the rest.
 
I messed with the cables, tried to tighten the crimps up, resoldered a few of the pins that looked questionable, and still nothing. I put test switch 1 on during game play and the lines went away, but the sound got awfully distorted with a louder hissing sound. turning switch 1 back off made the lines reappear and the sound back to normal. I checked the edge connectors, and still nothing. My voltages are good.. +12.06, +5.08, -5.14. I've removed the boards many times, checked solder joints and still can't seem to get anywhere. game plays just fine. Any other suggestions?
 
could this be a video sync issue? Game play is fine, and I actually got my best score ever playing with these lines on the screen. All the test modes work just fine.
 
I haven't tried swapping any ram.. I don't have any, but looking closely, the ram at 10h, which is a 4118A chip does have discolored legs.. None of the chips are socketed unfortunately. What other chips should I be looking at?

The test mode did pass the ram test as well as all others, with the exception of the HS save ROMs. This problem didn't start until I reworked the sound board and replaced the 2 timers and the 4558C chip. I showed a buddy my pictures and he thought it looked like a sync issue. I did socket the 555 chips, which he said he wouldn't have done. I also socketed the 4558 chip.
 
Got it working..

It ended up being a jumper on the 555 chip. There are 2 pins that were jumped together on the original chips. After desoldering, I noticed there was a trace on the board, so I didn't put too much effort into joining the pins with solder. Tonight I decided to solder a jumper between the 2 pins and that fixed it. Guess there is something wrong with the trace on the board.
 
Got it working..

It ended up being a jumper on the 555 chip. There are 2 pins that were jumped together on the original chips. After desoldering, I noticed there was a trace on the board, so I didn't put too much effort into joining the pins with solder. Tonight I decided to solder a jumper between the 2 pins and that fixed it. Guess there is something wrong with the trace on the board.

Glad you got the problem resolved:)
 
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