input selector has started going Godzilla on me...

Just out of the blue it will start switching from cd to tuner to tape to whatever, over and over and over again. Even my remote does not stop it. I have to send it in to have it looked at, but I wonder what it means now. There could be a lot of different reasons, but I wonder if anyone else has had this problem and what some of the causes might be. Could it be suffering from a sort of electrical alzheimers condition? Kicking it and throwing it out my second floor window didnt seem to help.
Does the input selector on the unit itself rotate 360* or does it have specific stops on each end of the rotational spectrum that keep it from continually rotating? Sean
it rotates 360. Its an annoying thing. Now, of course, the knob itself is not moving even as the source selections light up as they are being selected and bypassed. It clicks to indicate you have arrived at your selection. It is clicking a lot since it never actually settles on any one selection. Thanks for asking..