RobS is the best choice for Empeg repair -- he has access to schematics, original replacement parts, and by far has the most experience of anyone (current) repairing these beasts.

Stu/Eutronix (link at top) also dabbles, and can fix common problems. But troubleshooting capabilities appear limited, due to no schematics and the need to recoup time spent diagnosing things.

I also repair empegs, but encourage people to go elsewhere first, and treat me as the option of final resort. I can diagnose/fix nearly anything, even without schematics. But shipping things to me in Canada can be pricey at the border.

Cheers