Audio Systems: yamaha rx-570 issue, open case, extension tube

Question
We own a yamaha rx-570 receiver. It's been great up until recently. The input knob seems to be having issues. The sound is generally fine when it's set to the tuner but the sound breaks up considerably when you try to listen to the devices hooked up to the other inputs. Crackling, fading in and out of the speakers, some distortion. We have to move the knob several times to get it working properly and even then it's sketchy.

I don't wish to replace it if I can manage it, but is it worth repairing? Is it something I can do myself or should I take it to a repair shop?

thanks for your time.

Answer
all you need to do is get a can of control cleaner with lubricant, such as de-ox-id, open case of stereo so you can see the rear of controls and give a little spritz through the opening, probably see a small hole to stick the extension tube that came with cleaner, work controls back and forth repeatedly and you should hear an immediate improvement, should last for several years...