What was found
DURING CRUISE, ACFT DIVERTED DUE NR 2 IDG OFF BUSS, GLC 2 FAULT, CMC MESSAGE, AT STATION. PERFORMED FIM 24-21-00-810-850-A AS T/S SWAPPED GLC 2 WITH APU ALC, TEST IAW AMM 24-21-21-400-801-A, TEST WAS SATISFACTORY, ADDITIONALLY CHECK WITH ENGINE RUNNING IAW AMM 71-00-01-910-801-A WORKING FINE. THE ACFT RETURN TO NORMAL OPERATION.