As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED LEFT N1 GAUGE BECAME ERRATIC WITH A CORRESPONDING INCREASE / DECREASE IN ENGINE PERFORMANCE DURING CLIMBOUT. CREW RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED, REMOVED AND REPLACED LEFT CONTROL AMPLIFIER AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT RELEASED FOR SERVICE.