What was found
NR 1 ENG IDG DRIVE LIGHT INOP. REF WD 24-11-11, WD 24-11-71. TRIED NEW GCU, NO HELP. RE-INSTALLED ORIGINAL GCU PER MM. DRIVE LIGHT STILL INOP. DRIVE INDICATOR NOT DISPLAYED ON ELECTRIC SYNOPTIC PAGE. DRIVE LIGHT INOP STARTED AFTER NR 1 IDG RPLMT FEB2. ORIGINAL PROBLEM WAS IDG NOT COME ONLINE. SUSPECT A BAD IDG FROM STOCK. RINGOUT OIL PRESS SW IN IDG AND WIRING REF WDG24-11-11. REPLACED NR 1 ENG IDG PER MM. ALSO REPLACED NR 1 ENG IDG CARBON SEAL PER MM. OPS AND LK CK'S OKAY.