As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING PRE FLIGHT TEST OF HYDRAULIC SYSTEM, THE PILOT OPERATED THE TEST SWITCH ON COLLECTIVE CONROL AND THE CYCLIC CONTRO EXPERIENCED HARD OVER TO THE LEFT. TEST WAS REPEATED WITH SAME RESULT. AIRCRAFT GROUNDED AT 2330 FOR TROUBLESHOOTING IN THE MORNING. SUSPECTED SERVO (LEFT AFT) REPLACEDWITH OVERHAULED UNIT S/N 1227 GROUND RUN AND SERVO TEST COMPLETED SUCCESSFULLY AIRCRAFT RELEASED FOR SERVICE. (TC# 20090812008)