Sound Interference. I keep getting a terrible interefence on the sound through this unit. This

Question

I keep getting a terrible interefence on the sound through this unit. This will only clear by unplugging the unit, leaving for a few minutes and and plugging back in. This always clear the interferences but it always returns within a day or so.The interference is worst when watching the TV through the DVD channel or trying to record on the unit but can also occur when watching pre-recorded discs.I also suffered the loading problem on start up but this was repaired about a year ago.Are the prioblems connected and how can I resolve?