I am working on a MV2F that started off doing nothing. I replaced the LSPC2-A2 to restore sync, and then the NEO-I0 after that to actually get an image on screen. With the Neo Diagnostics BIOS, the text is unreadable as it is either the wrong characters or has dots and lines all over.
On the UniBIOS, the crosshatch is there but is also messed up as it has the wrong tiles and characters selected. I noticed that it seems to be the lowest bit stuck, as R becomes S, H becomes I, F becomes G, etc.
With a game inserted, the NEO GEO logo is just white lines, there is no sound, and the game itself (Neo Turf Masters) is little more than white lines and blocks. This board had some minor battery leakage on it, but the traces near the NEO-ZMC2 and NEO-257s I checked first were all good.
I'm unsure where to look next. I swapped the NEO-G0 on a whim to no avail. I feel like this board might have been overvolted at some point considering both of those custom chips had faults, so I wouldn't be surprised if I had to replace more of those.
Any ideas would be appreciated.
On the UniBIOS, the crosshatch is there but is also messed up as it has the wrong tiles and characters selected. I noticed that it seems to be the lowest bit stuck, as R becomes S, H becomes I, F becomes G, etc.
With a game inserted, the NEO GEO logo is just white lines, there is no sound, and the game itself (Neo Turf Masters) is little more than white lines and blocks. This board had some minor battery leakage on it, but the traces near the NEO-ZMC2 and NEO-257s I checked first were all good.
I'm unsure where to look next. I swapped the NEO-G0 on a whim to no avail. I feel like this board might have been overvolted at some point considering both of those custom chips had faults, so I wouldn't be surprised if I had to replace more of those.
Any ideas would be appreciated.