Gordon crane technicians continued their troubleshooting on this Tuesday. They found the crane up-limit protection switch which is installed on the same bracket with the the crane down view camera is broken. The spring inside the limit switch  which is used for pushing the action plunge out in the switch lost its function. This up limit switch is the last protection for the crane so it is set as when it is in action the crane main contact coil  which controls crane  power supply will be in open position. The broken switch is replaced by a new one( same type) on this Wednesday. The crane annual inspection has been  finished after the switch replacement. The crane works fine now.