As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE NO2 ENGINE FAN VIBRATION INDICATOR WENT TO 4.0 FOR 10 MINUTES DURING CRUISE FLIGHT. THE CHECKLIST WAS RUN. NO OTHER ENGINE PARAMETERS EXCEEDED. FAN VIBRATION THEN OSCILLATED FROM 4.0 TO 0.2 BACK AND FORTH. ON APPROACH, VIB WAS STABLE AT 0.2. THE MAINTENANCE VENDOR TROUBLESHOT AND DETERMINED THE RH ENGINE ACCELEROMETER WAS DEFECTIVE AND WAS REPLACED WITH A NEW UNIT. OPS CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE