just to be clear, this isn't a player bug, it's a hardware problem. the correct way to fix it is to have a capacitor installed on the display board, as outlined in the FAQ.
if you cut the dimmer wire, you will still suffer from the random brightness setting when the empeg powers on. you would be immune to problems when turning on and off your lights, though. if you think it would be less annoying to deal with the problem only once each time the machine boots, go ahead and disconnect the wire, but i think you're going to want to get the problem solved fully. the only way to do that is to get the capacitor installed.
there are people here on the board who offer the service of installing this capacitor for a modest fee, if you're uncomfortable soldering small parts.
good luck,
--dan.