What was found
RTD AT ESSA 19R FOR NR 1GEN FAULT AND MASTER CAUTION AT 60 KTS. ACCOMPLISHED RTO CKLST AND RETURNED TO GATE. NR 1 GEN, DID NOT AUTOCONNECT ON STARTUP, HAD TO ADVANCE THROTTLE AND RESET GEN 1 SW. ON TAXI BACK GEN 1 MADE CLICKING SOUND CONNECTING AND DISCONNECT SEVERAL TIMES AND FINALLY STAYED CONNECTED UNTIL SHUTDOWN. A/C RELEASED FOR SERVICE PER MEL 24-11-01. REMOVED AND REPLACED NR 1 GCU AS PER MM:24-22-12-4. NR 1 ENGINE RUN PERFORMED BY EMP NR 181214. NR 1 GEN CAME ON LINE NORMAL.