trouble with volume on a marantz 2225

Hi to whom it may concern
I have a Marantz 2225 since it was new (1979?) and the Volume seems to have a dead spot just when you turn it on, I only get one channel (right) until I turn up the volume the left comes in and then its ok even if I turn the volume down and up both channels stay on so
any ideas?
I can live with it but its annoying
Remove the top cover and spray a little electrical contact cleaner in the volume pot.
Could possibly be the ageing process of the Marantz..Had the same problem with my 2230 and it was that way for many years..I just assumed ( after cleaning pots etc..) that one side took longer to warm up...Once i kicked the volume control up it would straighten itself out..If the cleanng doesn't solve the problem,just live with it......