Input Selector

[KENWOOD KA-7090R]

KENWOOD KA-7090R - This amplifier is old but still works.

However, in the last two months the following problem has come up:

INPUT SELECTOR button keeps jumping by itself between sources: Tuner, Aux, Phono, Tape etc... causing audio sound to stop whilst listening to music.

It's like the dial has become "static" and works better and jump less if you turn it very slowly (clockwise or anti clockwise).

I was wondering if there is something that can be done to stop this from happening i.e. cleaning or possible repair if not too expensive.

Thank you.