As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS ON DESCENT LEFT ENGINE WENT TO 2.0 TO 2.3, AT FLIGHT IDLE THEN BEGAN TO FLUCTUATE. MAINTENANCE REPORTS VIBRATION WITHIN LIMITS IAW AMM 71-00-00. ***SUPPLEMENTAL INFORMATION: MAINTENANCE ACCOMPLISHED #1 ENG FAN BALANCE IAW CARD 77-95-12.*** (CLOSED)