I own a MixWiz 16:2 DX which was having an issue on one channel. I figured I would just get a spare channel strip from an authorized dealer, and fix the old one.
Sadly, I was informed that my ole mixer doesn't even have spare parts being made for it anymore (apparently went out of production in the late 90's), but the guys at American Music and Sound offered to send me the schematics so I could diagnose it myself.
They didn't just stop there. They even had one of their senior techs send me some advice on what to check.
I just thought that it was nice for a change to find a company that is out there doing good customer service for us poor guys down in the trenches in live sound. I have had more than my share of bad experiences with service from different companies, it is nice to share a good experience
FYI, Agedhorse actually had the advice that fixed the problem .... but we all appreciate him publicly and often