What was found
AFTER LANDING, SHUTTING DOWN NR 2 ENGINE, ACFT MAIN ELECTRICAL BUSS POWER WOULD NOT ACCEPT GROUND POWER. STARTED APU TO ESTABLISH ELECTRICAL POWER ACFT GROUNDED. FOUND CIRCUIT BREAKER MAIN BUSS 2 INSIDE P-92 PANEL OUT. RESET BREAKER, DURING TAP TEST AROUND CIRCUIT BREAKER TRIPPED. REMOVED P92 PANEL FOR CIRCUIT BREAKER C817 REPLACEMENT. R & R C817 CIRCUIT BREAKER & REINSTALLED P92 PANEL REF MM 24-21-21-400-801 ALL OPS CHECKED PASSED. COMPLETED AC & DC OPS CHECKS IAW MM 24-21-00-700-803 & MM 24-31-00-700-801 P92 PANEL OPS CHECKS FOR INSTALL COMPLETE & NO FAULTS NOTED. REPLACED EXT PWR CONTACTOR C937 REF. MM 24-41-12 OPS OK. REPLACED GEN CONT BREAKER NR 2 C802 REF MM 24-21-41-000-801. OPS CK OK. REPLACED BPCU NR 2 OPENED & CLOSED C/B A-12 ON P92. OPS CK OK. REPLACED ACFT SYS GENERATOR & APU MODULE REF MM 24-21-51-000-801. OPS CK OK REF MM 24-21-00-700-803 VERIFIED WIPER. OPS OK ALSO. WHILE RUNNING ENGINES CYCLED POWER BETWEEN EXT PWR-APU PWR-& BOTH ENGINE GENS NUMEROUS TIMES IN MULTIPLE SEQUENCES. NO DEFECTS NOTED. VERIFIED OPS CHECK NORMAL, REF 24-21-51-000-801.