After 11 faithful years of service, my Cambridge A500 amp has finally developed it's first problem. As of last night, when I adjust the volume with the remote, the motor behind the volume knob makes a sort of grumbling noise when it's adjusted. There's no static involved, and no noise when manually turning the knob, just the noise from the motor when activated.

Are there any tweakers that have a remedy for this? Is it something that can be resolved by cleaning the motor or adding some low weight dielectric lubricant?