What was found
WHEN I TRIED TO SWITCH FROM EXTERNAL POWER TO APU POWER, THE APU WOULDN T HOLD THE LOAD. EVERYTHING IN THE COCKPIT FLICKERED WITH AUDIBLE CLICKING AND GRINDING SOUNDS AND THERE WAS A STRONG ELECTRICAL BURNING ODOR. SWITCHED BACK TO EXTERNAL POWER AND THE APU STILL RUNS WITH AIR BUT AFTER MAINTENANCE HAD US TRY AGAIN, THE APU STILL WILL NOT HOLD THE LOAD. AMM 24-50-00-5 P-34 PANEL REMOVAL, REPAIR AND REINSTALLATION AS WELL AS FEEDER WIRING REPAIRS ARE DOCUMENTED ON INDIVIDUAL WRI'S TSI 24-00/6632 ADDRESSED INDIVIDUAL MAINTENANCE OPS CHECK TASKS. ELECTRICAL LOAD DISTRIBUTION ADJ/TESTS WERE PERFORMED AND CHECK NORMAL, REF AMM 24-50-00-5. ALL TASKS COMPLETED & ACFT OK FOR SERVICE.