As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKE OFF, TWO MINUTES AFTER TAKEOFF FROM BASE, NR 1 ENGINE OVERSPEED CAUTION LIGHT FLICKERED REPEATEDLY (BRIGHT NOT DIM). AIRCRAFT WAS RETURNED TO BASE. UPON LANDING THE MECHANIC REMOVED AND REPLACED THE NR 1 ENGINE SPEED SENSOR. AIRCRAFT WAS FUNCTION CHECKED AND RETURNED TO SERVICE.