Hello all, first time caller here. I have the RR2150 and recently it's been dropping a channel. Speakers, headphones, same thing. When it happens it can be fixed by rapidly turning the volume knob up. My diagnoses is that the volume contact needs cleaning. Two questions:

Outlaw tech support told be there are two versions of this receiver, one that allows you to clean the contacts and one that does not. How do I know which version I have without opening the unit?

Assuming I have the version that can be cleaned, any help on how to?

Thanks