As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AUTOFEATHER TEST, NR 2 PROP WILL NOT FEATHER. RPM DROPS FROM 650 TO 590. ALL OTHER PARAMETERS OK. R & R RELAYS 6121-K4, K2 AND K10. SLAVED IN NR 2 TSEU, NO FIX. ORIGINAL TSEU REINSTALLED. R & R NR 2 PCU IAW 61-10-10R. NO FIX. R & R AUTOFEATHER SELECT SWITCH. OPS CHECKED GOOD.