What was found
NR 1 SOURCE OFF LIGHT ILLUMINATED, NR 1 GEN DRIVE LIGHT ALSO ILLUMINATED. ACFT GROUNDED. PERFORMED BPCU BITE PROCEDURE 24-41, TASK 801. NO FAULTS FOUND. PERFORMED NR 1 ENG GCU BITE PROCEDURE 24-21, TASK 801. NO FAULTS FOUND. ALL SYSTEMS ARE GREEN. INSPECTED OIL QTY, GOOD. ACCOMPLISHED GROUND RUN-UP OF NR 1 ENG IDG, FOUND NR 1 IDG DRIVE LIGHT ILLUMINATED AND NR 1 GEN OFF BUS LIGHT ILLUMINATED. NR 1 IDG TRIP OFF LINE, WHILE NR 1 ENG IS RUNNING. FOUND IDG WAS DISCONNECTED ON THE ENGINE IAW AMM 24-11-00-700-802 AND FIM 24-21 TASK 821. PERFORMED NR 1 IDG DISCONNECT AND CONNECT TEST. ACCOMPLISHED SECOND GROUND RUN-UP, NR 1 IDG OPERATED NORMAL IAW AMM 24-11-00-700-802. REPLACED & TESTED NR 1 ENGINE IDG REF MM 24-11-11/401. GROUND VERIFICATION OF FAULT RESOLUTION FOUND TO BE SATISFACTORY IAW FIM 24-21, TASK 821. NO FILTER CONTAMINATION NOTED AT REMOVAL.