If your A40640 is damaged and similar to the figure below, we provide a repair method:
Note: This fix applies only to N40640 v1.2 and v1.3 laser drives, You can find the driver version number on the other side of the driver board.
Please note that when disassembling your laser, please remove the four screws on the fan first:
How to fix it?
Way 1: remove the damaged components, and then connect the following two welding positions with a section of wire, as shown in the figure below:
Way 2: If the burn is too serious to weld, you can also try to scrape out the wire with a knife on the PCB wire, as shown in the following figure
Then weld as shown in the figure below:
The following is the rendered image. All you need to do is connect the two ends of the red wire. You can also connect them according to the blue wire, and your laser driver will be repaired.
Note: the connecting wire should not be too thin.