Quoted from thedefog:Poor grounding is the biggest issue I've experienced on DE games. Sometimes it is as stupid as tightening the screws on the audio board. That, and digital ground isolation in the actual design isn't the greatest, but then again these were meant to be operated in noisy areas.
There's an entire thread on this somewhere in the Data East section but using nylon washers when mounting the sound board - thereby isolating those contacts from the backbox ground plane - is what many have found to be effective in greatly reducing the hum.
Boca Raton, FL
