As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT REPORTED THAT WHEN HE TRIED TO PULL THE COLLECTIVE UP, IT FELT VERY HEAVY. IT WAS NOTED DURING TROUBLESHOOTING THAT THE SPOOL VALVE WAS VERY DIFFICULT TO MOVE AND THEN IT WOULD ONLY MOVE A SMALL AMOUNT. A SERVICEABLE SERVO WAS INSTALLED AND CONTROLS CHECKED OUT NORMAL.