What is the method of resolving common faults in the operation panel of sewing machine of sewing machine?

Common troubleshooting of sewing machines for sewing machines:

First, there is no reaction to the boot, the panel indicator light is not on

This kind of failure is generally due to the circuit board power supply part of the operating panel being broken or abnormal. If there is no fault inside the machine control box, the focus should be on checking whether the connection line between the control box and the operating panel is broken and check it one by one. If the connection wire is in good condition, check whether the plug and socket are connected reliably and whether there is any place where the welding points are broken; If the failure is still after inspection and treatment, it means that the circuit integration block inside the panel is damaged. Since most of these circuit boards are patch circuits, only the entire circuit board can be replaced for repair.

Second, abnormal speed regulation

Most of these faults are caused by poor VR1 speed regulator. If the VR1 slider is dirty and causes an abnormal speed adjustment, the following method can be solved: disassemble the operating panel, remove the VR1's lever, and wipe the semiconductor with a small amount of non-fat cotton with anhydrous alcohol. Clean the surface and install the lever after the contact surface is air-dried. If the VR1 is seriously worn or the internal circuit is broken, the entire VR1 potentiometer needs to be replaced.

III. Failure of some function keys

Such failures are divided into two situations:(1) Turn on the power switch, some functional keys fail and the buzzer is silent; (2) Turn on the power switch, some of the function keys fail but the buzzer's key prompt sound is normal.

The former fault is generally caused by the contamination of the conductive rubber in contact with the circuit board or the damage of the conductive rubber in the key, which causes the trigger pulse signal to fail to form. The maintenance method is to open the circuit board and check whether the conductive rubber of the faulty button is damaged or dirty at the contact with the circuit board. If the button is damaged, it is replaced directly. If the contact is poor, the non-fat cotton ball is stained with a little anhydrous alcohol to wipe the contact surface. The latter type of failure is generally caused by the failure of the individual pin function of the CPU on the circuit board and can only be solved by replacing the circuit board.

Innormal LCD Display

Most of these failures are caused by moisture on the display screen or poor contact between the keyboard circuit and the plug socket of the display cable. If the screen is damp, electric heat dryer can be used to drive away the moisture; For poor contact with plug sockets, check for troubleshooting as described below: If the main screen fails, please check whether the CN102 plug socket is malsoldered or has poor contact, and then check whether there is a break in each connection, and handle it separately; If the bottom line residual display is malfunctioning, check whether the CN103 plug socket is falsely soldered or has poor contact, and then check that there is no Breakpoint in each connection, and deal with it separately. The failure can be eliminated.