What was found
PILOT REPORTS LEFT GEAR WILL NOT COME DOWN. C/W GEAR SWINGS WITH HYDRAULIC CART, COULD NOT DUPLICATE PROBLEM. LUBED GEAR, CHECKED RIGGING, REPLACED UPLOCK ROLLERS. FLEW AGAIN, SAME PROBLEM EXISTS. CHANGED LEFT GEAR ACTUATOR AND HYDRAULIC PACK, GEAR CHECK GOOD AGAIN IN HANGAR. FLEW AGAIN, SAME PROBLEMS. LAST RESORT, CHANGED DOWNLOCK SWITCH, FIXED PROBLEM.