There are two reasons why the laser marking machine does not respond after changing a foot switch:
1. The signal line is not connected to the interface.
Check whether the 1-pin and 14-pin or other pin ports of the con4 interface of the laser marking board are connected.
2. Software settings.
It may be that the software has been reset, and the input port needs to be set in the software Param(F3) – Port – Start Mark IO. There are 15 ports in it. If you are not sure which port is used, you can test them one by one until the foot switch responds.

3. The foot switch of the laser marking machine is damaged.