What was found
R GEN OFF EICAS IN FLIGHT. REMOVED AND REPLACED RT ENG IDG. CHECKED FOR OPEN CIRCUIT BETWEEN IDG TERMINAL N AND GROUND, NO CIRCUIT OPEN IAW WDM 24-21-11 / 24-21-21. ACCOMPLISHED OPS CHECK OF IDG, LEAK CHECK GOOD IAW AMM 24-11-01/401. RAN ENGINE IAW AMM 71-00-00. SYS OPS CHECKS GOOD. REMOVED AND REPLACED RIGHT GCU (OFF PART: P/N 734284F, S/N 4502).