As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING TAKEOFF ROLL, CREW NOTED THE LEFT ENGINE BETA LIGHT DID NOT EXTINGUISH WHEN THE RIGHT WENT OUT. WHEN THE ENGINES ENTERED PROPELLER GOVERNING MODE INDICATING A PROBLEM THE CREW ABORTED THE TAKEOFF. INVESTIGATION FOUND THE UNFEATHER BUTTON HAD STUCK IN THE ON POSITION. THE SWITCH WAS LUBRICATED AND ACTIVATED AND SUBSEQUENTLY TESTED OK.