Neo Geo MV1FZS Graphic problem(black bars)

[fixerpro]

Hi, i have a strange problem on a mvs MV1FZS. I bought like 50 broken mvs bases about ten years ago and now im trying to repair some, but im stucked on this strange problem never seen on others mvs.
Seems graphics missing vertically with black bars.
I made a video of this.

already changed NEO-ZMC2, and various small chips(74lsxxx) with no result.

Have any idea? thank you

 

[channelmaniac]

Look for missing signals to the ZMC2... There's one that tells it which 8 bits to shif out and if it's stuck/missing, you'll get that kind of striped screen. It's one of the low numbered pins.

 

[fixerpro]

Look for missing signals to the ZMC2... There's one that tells it which 8 bits to shif out and if it's stuck/missing, you'll get that kind of striped screen. It's one of the low numbered pins.

Thank you for your reply, I already repaired 10 mvs boards with your repair logs. Now i investigate on that signals and will update the thread.

 

[fixerpro]

checked the signal on pin 7 and it seems good, it pulsing.