As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTO PROP FEATHER TEST FAIL RT & LT ENGS. LT PROP LINGERS BETWEEN 670 & 680 RPM, TORQUE BETWEEN 13.5 & 16.1. RT PROP LINGERS BETWEEN 670 & 690 RPM, TORQUE BETWEEN 12.9 & 15.2. TROUBLE SHOT THE DISCREPANCY & FOUND A FAULTY LT & RT ENG AUTO FEATHER OIL PRESS SWITCH. R & R SAME. SYS OPERATIONAL CHECK WAS GOOD. ACFT WAS RETURNED TO SERVICE.