MV1B: Black Screen only with cart inserted


Neo Bubble Buster
Aug 17, 2018
I'm having a weird problem with this board.
I can access the bios menu, but as soon as I insert a game it hangs on a black screen.
With a 161 in 1 for example, I can get to the menu but if I choose a game, same thing, black screen.
Diagnostic Bios returns an "all test passed".

Has anyone experienced something similar? Any tips on how to proceed? I'm thinking it's maybe a clock related problem even though the diag bios did not
report anything bad.

I had a similar problem before with a Mv1c but it was a bad ram in the backup area, and only affected some games, other games would work fine.