MV-1FZ picture/resetting problem

Hi. I've just recently started experiencing a strange problem with my MV-1FZ board. Whenever I start a game everything is fine, but a few seconds later the screen begins to get progressively more wavy, and ultimately starts either momentarily turning off, or simply resetting. Actually, it doesn't exactly power off, the picture just disappears for a second then returns. I've cleaned both the cart and jamma contacts, and this problem happens with all of my neo games. Any ideas?

could be a bad power supply.

I thought it might be the power supply too, but my CPS2/3 games work fine with it, and my MVS board is getting +5 and +12 volts (I checked it with a multimeter), so I'm not really sure. Is there anything that could suggest that a power supply is bad, even if it is outputting the proper voltage?