What was found
AUTO PILOT AND AUTO THROTTLE DISCONNECT LT GEN DISCONNECT ALSO R ESET GEN REMOVED AND REPLACED LEFT ENGINE IDG PER AMM 24-11-01. NO HELP. INSTALLED IDG WILL NOT PRODUCE ANY VOLTS OR FREQ''S AS WELL. TRIED KNOWN WORKING GCU''S AND SENT SERVICEABLE GCU PER AMM 24-22-02 STILL IDG STILL WILL NOT SHOW ANY VOLTS OR FREQ''S. INSPECTED ALL FEEDER LINES AND CANON PLUGS FOR CORROSION NO GENERATOR, INTE DEFECTS AT THIS TIME. ALL C/B''S ARE FOUND IN THE CLOSED POSITION ASSOCIATED WITH THE LEFT POWER GENERATION . WILL REQUIRE FURTHER TROUBLESHOOTING. ROTABLE PARTS CHANGE WAS INDICATED - TT # 1981841 SN OFF 1532 RESET BUS TIE SWITCHES AND UTILITY SWITCHES PRIOR TO START A/C POWER . RAN #1 ENGINE PER AMM 71-00-00. ALL OPERATIONAL CHECKS NORMAL FOR LEFT IDG COMING ONLINE AND DISCONNECT . LEFT ENGINE IDG OPS CHECKS NORMAL. AIRCRAFT RETURNED TO SERVICE AFTER TALKING WITH TOMC.