What was found
(CAN) RADIO MASTER SWITCH CONTROLLING POWER TO ALL RADIOS E.G. DUAL NAV COM, VDR, TRANSPONDER, BECAME INTERMITTENT THEN FINALLY FAILED SHUTTING POWER OFF TO ALL THE RADIOS. MINIMAL PLAY IN TOGGLE SWITCH EVIDENT. REPLACED SWITCH AND NO MORE FAULT. TIME ON ORIGINAL PART UNKNOWN BUT AIRCRAFT BASED IN FLYING SCHOOL, THEREFORE MANY CYCLES SUSPECTED PERHAPS INTO THE THOUSANDS.