What was found
GEG - ON PUSHBACK FOR FLIGHT 4309 RECEIVED A "IDG 1 DISC" ON START-UP. PLACED ON MEL 24-11-1(A). AIRCRAFT RETURNED TO SERVICE. 1/15 MDC REPORTS IDG NR 1 INTERNAL FAULT. REMOVED AND REPLACED NR 1 IDG IAW CRJ AMM TASKS 24-11-01-000-801-A01 AND 24-11-01-400-801-A01. OPERATIONAL TEST OF THE IDG NR 1 FAILED PER AMM TASK 24-11-01-710-801-A01. FAILED OPERATIONAL TEST OF THE IDG DISCONNECT MECHANISM WITH ENGINES STOPPED AMM TASK 24-11-01-710-802-A01. MDC CONTINUES TO REPORT IDG NR 1 INTERNAL FAULT. CONTINUE MEL 24-11-1(A) CAT A PLACARD 353979. AIRCRAFT RETURNED TO SERVICE.