We see many Fender amps in for repair, it's not because they're unreliable its because they are a popular amp and therefore more likely to see. In particular we regularly repair hot rod deluxe, and deville combo valve amplifiers.
Repairs to fix these broken Fender amps include:
Fixing crackly pots
Replacing capacitors causing hum
repairing intermittent problems with amp breaking down
Re valving and biasing
Foot pedal repairs