Motorola 7 inch tabletop

[timmy]

Is it possible for a component such as a ceramic disc that goes from a given circuit to the chassis ground, which is one side of AC along with DC negative to go bad or short to let AC into the circuit. This set when it's turned off the speed of the hum quickly slows to a stop and the image as well shows it as a kind of ticking. But when it's at full 60hz you don't see it but hear it.