Joe,

Have you checked that the RC Valves move freely without the cables attached?

If the RC Valves have built up carbon deposits, they will start to get jammed, causing the servo to overload trying to turn to move the cables, to move the pulley's to move the rc valves. that is when the PGM will get overloaded and burn out.

Pull the cables off the pulleys on the RC Valves and check your valves.