What was found
AFTER PUSHBACK, PUT BOTH CONDITION LEVERS TO MAX IAW FLOW, NR 2 PROPELLER CAME OUT OF FEATHER BUT NR 1 PROP STAYED AT 190 FOR AT LEAST FOUR MINUTES. ONLY CAME OUT OF FEATHER WHEN POWER WAS ADDED. AIRCRAFT REMOVED FROM SERVICE. NO FAULTS IN CDS. REMOVED AND REPLACED NR 1 ENGINE OVERSPEED GOVERNOR IAW MM 61-20-26-000-801, AND 61-20-26-400-801 AS A PRECUATION. OPS AND LEAK CHECKED GOOD. COMPLIED WITH MULTIPLE PROPELLER UNFEATHERING ACTIONS. ALL NORMAL IAW MM 61-20-00-720-801. RETURNED TO SERVICE.