What was found
(CAN) DURING CRUISE FLIGHT WITH AUTOPILOT ENGAGED, PILOT NOTED THAT AIRCRAFT WAS NOT HOLDING ALTITUDE. PILOT DISENGAGED AUTOPILOT AND AIRCRAFT PITCHED NOSE UP. ELECTRIC ELEVATOR TRIM SELECTED BUT NO TRIM MOVEMENT. ATTEMPTED MANUAL TRIM BUT TRIM WHEEL WOULD NOT MOVE, SPRING BACK. PILOT MAINTAINED CONTROL OF AIRCRAFT WITH ELEVATOR AND LANDED WITHOUT INCIDENT. INITIAL INSPECTION UNABLE TO MOVE ELEVATOR TRIM. AIRCRAFT HANGARED FOR SHORT PERIOD AND TRIM OPERATION OKAY. ELEVATOR TRIM CABLE/CHAIN CIRCUIT INSPECTED, NO DEFECTS. LT AND RT TRIM ACTUATOR DISASSEMBLED AND FOUND MOISTURE. ACTUATORS INSPECTED AND LUBRICATED IAW MFG INSTRUCTIONS.