As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 PROPELLER DOES NOT UNFEATHER USING THE ALT FEATHER PUMP. TAPPED FEATHERING PUMP WITH A SMALL MALLET. PUMP STARTED WORKING BUT MADE AN ABNORMAL AMOUNT OF NOISE AND PUMP SPEED SEEMED TO VARY DURING UNFEATHER. REPLACED #1 ENGINE FEATHERING PUMP IAW Q400 AMM 61-20-31-400-801. OP CHECKS GOOD.