Just picked up a Robocop recently and am having the constant hum/buzz out of the speakers. It's not a sound that follows light matrix activity, but just a constant buzz. Read through this thread in its entirety and tried some of the things suggested. One interesting thing on my machine is when I float the sound board, instead of fixing the hum or making it better, it makes it a lot worse! In fact, floating any of the boards hurts instead of helps. Is this pointing to anything in particular being that I'm getting the opposite effect than most others? All the boards are screwed down tight with screws in all mounting holes.