I ran into the same problem recently. Turned on the EP350V3, and voila, humming. Quickly narrowed it down to my cable provider. Unplugged the incoming cable and no hum. Called my cable provider and explained the problem. The lady on the other end (call service in Atlantic Canada) didn't have a clue. An electrician friend of mine recommended a new power bar with the cable in/out feature. Works like a charm however the cable company is still at fault! Was tempted to try a video isolation transformer from Axiom.
