First we have to sort out whether there is a problem with the line. Look for a tool to block the probe of the high-position sensor, and observe whether the indicator light of the sensor is on. If the sensor is on, it means that there is no problem with the line. If not, consider whether the line head is loose.
Because this step is live operation, try to wear insulating gloves, to ensure safety, loosening wire head need to be strengthened by power cut, and then verified. The indicator lamp of the high position sensor can be turned on normally, but the needle can not return to the normal high position, so it should be adjusted as follows:
1. The indicator lamp can’t be turned on during the whole process of the needle’s up and down reciprocating movement. At this time, the needle will be set to a high position and remain motionless, and the inductor will be adjusted to move forward and backward until the indicator lamp just turns on.
2. The indicator light can be turned on during the whole movement of the needle up and down, but not at a high position. At this time, adjust the needle to a high position and keep it still, loosen the induction screw, and rotate the ring until the light just turns on.