As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACCOMP TASK CARD FOUND ENG 1 SHORT TIME FAULT MSG 77-21131 "THE N2 SPEED SENSOR SIGNALS DISAGREE". GROUNDED - YES. REF FIM 77-11-802. DISCONNECTED CH B AT THE NR 1 ENGINE N2 SENSOR. PINS 1-2 OPEN. REMOVED AND REPLACED NR 1 ENGINE N2 SENSOR IAW AMM 77-11-02. CLEARED NR 1 ENGINE FAULTS. GROUND VERIFICATION TEST IS GOOD.