What was found
RIGHT AC BUSS OFF EICAS, RIGHT AC MAIN BUSS IS NOT ENERGIZED RT AC BUSS OFF, RESET ONCE. AC BUSS OFF AGAIN 5 MIN LATER. RELATED NOTED FAULTS. PERFORMED BITE CHECK ON BPCU IAW FIM 24-20 TREE 801, FAULT NOTED ON RIGHT GEN POWER SYSTEM DP TRIP AND MAIN BUS/OVERLAP ZONE. HAD FLT CREW PERFORM ENGINE RUN TO DISCONNECT RT IDG AS A PRECAUTION. CONTINUE T/S IAW FIM 24-20 TASK 802, PAGE 18, FOR REMOVED IDG IAW AMM 24-11-01, INSTALLED IDG, PERFORMED LDEL LEAK TEST FOR OIL AND FUEL, ACP ENG RUN TEST OF IDG FOR NR 2 ENG IAW AMM TEST 71-00-00-501. NO LEAK FOUND. REQ INSPECTION AND COUPLE OF SAFETIED CONFIG 3, TEST #1 AND #2. IDG CK GOOD. ACP DISCONNECT TEST IAW AMM 24-11-01-206-001 TESTED GOOD.