As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)PILOT REPORTED THAT BOTH PROPELLER DEICERS, LEFT AND RIGHT, DID NOT SEEM TO PREVENT ICE BUILT UP AS THEY SHOULD. DURING BENCH TEST OF TIMER IT WAS NOTED THAT POWER WAS AVAILABLE AT BOTH OUTPUT PINS SI MULTANEOUSLY, CONTRARY TO THE MAINTENANCE MANUAL.