As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 330, NR 1 ENGINE HIGH VIB LIGHT CAME ON AND VIB INDICATED 4.5 UNITS ON CHANNEL A/B WHEN NR 1 THROTTLE WAS REDUCED TO IDLE VIB UNITS WERE IND. HIGH VIBRATION WAS INDICATED ON LOW SIDE ONLY. REPLACED FAN ASSEMBLY, THRUST RING, THRUST RING CARRIER AND AIR SEAL. PERFORMED GROUND AVM SURVEY PER M11-71-16 ON NR 1 ENGINE VIB WITHIN LIMITS. (M)