Qix White Lines On Border of Screen

64B1T

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Picked up this QIX cocktail today. A few days ago, it was known to be fully working, and I saw photos of it, but the previous owner moved it from one room to the other, and now it's got white lines across the screen.

I've taken the boards out and reseated everything that is socketed, but no change for the better - plenty of changes for the worse that I had to go do and tease back out, but the best I can get it to do is white bars.

Anyone seen this before?
 
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I would normally think this is a RAM issue of some kind, but it seems like someone in the past did replace all of them and nothing seems to be coming up in the RAM test? I realize now that the code 000101 is just the "test in progress" for the video board screen RAM, so not a failure per se.
 
I took some more photos of various configurations to see if that may help diagnose the problem more.

Color Balance and Intensity Screen
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Color Bar Screen
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Alignment and Convergence Screen
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At least in the color bar test, going from the manual, it seems like the RAM is working, but the addressing is not, somehow.
It seems that the issue is that bit 7 for ALL banks is pulled LOW... But only for certain addresses.

Bottom to top is $0000 - $00FF, and the pattern seems good from $0000 to $7FFF, but from $8000 to $B6FF it's having sporadic issues? Am I reading this right?

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Interesting that nothing is cropping up during the RAM self test, and that pattern of lines is different on every screen. For example, symmetrical during gameplay, and not at all seemingly present on the alignment screen.
 
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This seems promising. If something were wrong with one of those latches, it would explain the issue being present only on one side of the screen, and maybe why the RAM test is passing? Doesn't explain why every other set of the scan lines seemed messed up though. Maybe it's reading a stuck bit on that latch?
 
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Tried piggybacking U34, U70, U71, U84 and U98. No effect. Tried wiggling around all referenced chips, no effect. I did not have any LS139 or LS32 in stock for U87 and U88
 
Okay, so the white lines was a LS299 chip. However, now that it seems to be working properly in single player mode, it *refuses* to go into Tabletop mode. Is this another LS299? What is this?

 
For anyone following along....

The issue with the flipping to cocktail mode was the LS175 at U104. It had been corroded and destroyed, I suppose.

All good now, seemingly.

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