MAME, screen flashes, or goes black when pressing coin button

[Dannymh]

I have an IPAC and arcade VGA and when I press the coin button when the game first loads up the goes black it looks like the entire thing flashes to black almost like it oges off and on.

it isnt a long flash but more than I would normally expect. Would this indicate that something somewhere is not grounded correctly?

Dan

[Bobulus]

That would be my guess. You rule out a weird software issue by hooking up a keyboard and hitting the coin button (5 by default) and seeing if it does the same thing. If it doesn't, you know it's a hardware issue, like grounding.