What was found
DURING PRE-FLIGHT, CAPTAIN NOTICED 2 MOMENTARY CAS MESSAGES PRIOR TO THE APU GENERATOR AUTO-SWITCHING TO OFFLINE, AND DU2 LOSING POWER. THE CAS MESSAGES DISPLAYED WERE THE AMBER "APU GENERATOR OVERLOAD", AND THE BLUE, "R 60 HZ POWER FAIL". THE 60 HZ CONVERTER IN THE AFT EQUIPMENT BAY WAS CHECKED AND FOUND A STRONG ODOR. THE INVERTER WAS FOUND TO HAVE HOLES BURNED THROUGH THE METAL FRAME OF THE INVERTER. THE ACFT WAS MEL`D WITH 24-15.