failure speaker kenwood (comes backin when volume turned up)

[piggybattery]

Hello I have a kenwood kr-a5040 and I have audio problems. Sometimes one of the speakers falls out under a certain volume, when I turn-up the volume the speaker comes back-in.

Does anyone know how I can fix this problem?

I do not have experience in repairs, but I hope that I can solder it myself.

[minnie]

If it's the old potentiometer style spray the pot with electronics/contact cleaner.