Power supply

Possibilities: Transformer, reducing the input voltage to the components, or the power switch itself. Both can be checked with an Ohm meter, but first UNPLUG this unit, BEFORE attempting any repairs or testing. I know, it sounds like a lecture, but there are many who think it's unplugged and tear into it, and @*%!)${^%, they get a nasty shock! So, be safe first. Make sure the power cord plug is in your sight, both lugs are looking at you, and then proceed.