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 PROPELLER SYNC FAULTED, THE CREW ADVISED, WHEN ENGAGED THE LEFT PROP WOULD SPEED-UP 25 TO 30 RPM. THE DISCREPANCY WAS DEFERRED FOR CONTINUED OPERATIONS. THE MAINTENANCE TEAM TROUBLESHOT AND DETERMINED THE LEFT PROP SYNCHRO PHASER PICK UP WAS DEFECTIVE AND WAS REPORT WAS REPLACED WITH A NEW UNIT. OPS CHECKS WERE SATISFACTORY. THE AIRCRAFT WAS RETURNED TO SERVICE.