1. use multimeter to measure the plug 4 in the control box connected to the outlet of the power board CZ6, and the AC voltage of the 5 pin should be 63V.

If not normal: remove the embroidery frame.

2. use the multimeter to measure the DC voltage of the 2 and 3 legs of the CZ3 on the power supply board of the control box should be 90V + 10%. If it is not correct, check whether the inserting part is in good contact, and replace the power board.

3. check whether the magnetic connection line of the buckle line to the power board is reliable.

4. use the multimeter resistance file to check whether there is a short-circuit phenomenon between the magnet lead and the rack (resistance is 0): check each button magnet in turn and replace it, and the correct resistance should be 10 ohms.

5. check whether the main control panel has thread output. Is the L32 (KX) button lit? If L32 (KX) does not light, it indicates that there is a problem in the control panel (no signal output): replace the main control panel.

6. check whether the connection of the main control panel to the power board signal is reliable.

7. measuring the power plate triode M5 with multimeter is normal? If there is any problem: replace the same type pistor.