intermittent center channel volume
please help! my older jvc av receiver's center channel volume intermittent goes down to a much lower level. if i manually raise the volume (via digital center channel volume control on the receiver or on the remote) to max, the volume pops back to the proper level. there is no effect if i lower the volume. to me, it behaves like an old nondigital dirty volume rheostat. i checked the speaker cables and they're fine.
should i open the receiver and squirt electrical contact cleaner on the probable control? or should i give up and just turn it in to the service center? thanks for any advice.