Sprites glitches on Mazinger Z (Cave 68000) PCB.

[TorSKY]

Hello,

I've bought a Mazinger Z weeks ago for my game center and it worked fine. But recently start to have some glitches.

Tuesday: OK for 8 hours
Wednesday: Ok for 7 hours, then a small bug: each time there was a dark zone beside a white zone, there were some pixels waving between the 2 zones
Thursday: OK for 8 hours
Fryday: Ok for 7 hours, then a big problem with sprites not properly loaded
Saturday (today): Same sprite problem since the beginning of the day.





Roms look OK (noted OK when the game starts). Maybe a video memory error ? hope nothing to du with the custom UC that I won't be able to find spare to replace.

If anyone know the issue, already saw something like this, or have any idea of which component I have to check, thanks in advance for your help.

Regards

[vibribbon]

does any of the chips get hot to the touch when the game has been running for a while?

[TorSKY]

Most of them are a bit hot. But nothing that looks abnormal. And since last saturday the glitch appears even when I just turn on the game (so the chips are cold).

I bought some heat sink to install on chips.

But I also think there's a problem with the Video RAM. I bought a couple of new RAM (for the tremendous price of 5€ ! ). Waiting to receive them.