Trouble diagnosis and repair of a certain tool position in the tool holder that does not stop rotating, but other tool positions can rotate

1. The Hall element of this tool position is damaged. Confirm which tool position causes the tool holder to rotate continuously, enter a command on the system to rotate the tool position, and use a multimeter to measure whether there is a voltage change between the signal contact of the tool position and the 24V contact. If there is no change, it can be determined that the Hall element of the tool position is damaged, and the sending disk or Hall element can be replaced.
 
2. The tool position signal line is open, causing the system to be unable to detect the tool position signal. Check whether there is an open circuit in the connection between the tool position signal and the system, and connect it correctly.
 
3. There is a problem with the system's tool position signal receiving circuit. Replace the motherboard after confirming that there is no problem with the Hall element of the tool position and the connection between the signal of the tool position and the system.