What was found
AIR TURN BACK. EMERGENCY DECLARED, LOAD SHED ISLN BUSS TIE 1, 3, 4 ALL OFFLINE ONLY NR 2 BUSS TIE CLOSE, EICAS MESSAGES FOR ALL LOAD SHED. ATB 24:00 FOR PAN PAN. ELEC GEN SYS 2, ADVISORY MESSAGE 24261 DISPLAYED, FIM TASK 24-11-00-810-805 (GCU & IDG REPLACEMENT), SO R/R ENG2 IDG PER 24-11-01/401, ACFT STILL HAVING ELEC GEN 2 OFF MSG ON, NEED MORE T/S. CONFIRMED ENG 1, 3, AND 4 GENS ARE FUNCTIONING WITH ENG 2 DISCONNECTED.