As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 3217 - LYH-PHL - AFTER LANDING, THE NR 2 PROP STABILIZED AT 650 RPM. THE CREW CYCLED THE CONDITION LEVER TO START FEATHER, THEN BACK TO MINIMUM AND THE PROP WOULD NOT COME OUT OF FEATHER. REMOVED AND REPLACED THE NR 2 ELECTRONIC CONTROL UNIT.