Gain knob on Blackface working like an on/off switch

[lhrocker61]

I picked up a RM50 that came with a blackface module with an issue. All the way counterclockwise there is no sound. As soon as you move it a little clockwise, you have an overdriven tone like the knob is fully clockwise. The tone is the same the whole rotation clockwise. Does this sound like an issue with the gain pot or something else. I wasn't really planning to use this module as I have a tweed that goes from clean to drive pretty nicely. Just wanted to know what it would take to get this looked at and repaired.

 

[Lespauled]

Try cleaning the gain pot with Caig DeOxIt or some other contact cleaner.