Neo Geo monitor troubles

I just sold a guy (who happens to work at Harmonix- cool!) a Neo Geo cabinet. I hadn’t had any problems with it, but now that he’s using it, the monitor kind of blips out after 15 minutes or so of use. Rebooting the machine does the trick, but that’s a hassle, and anyone with a cabinet knows what kind of juice that sucks up.

Any ideas? He tried cleaning out the cab, and all the connections seem fine. We’re thinking it might be a voltage issue. He’s going to buy a new cord in the interim.