Soluzione: The probability of failure of these modules is very small, but once there is a problem, it will suffer huge economic losses, so under the premise of keeping the power supply stable, be extra careful when unplugging the module or handling the switch. When troubleshooting such faults, first ensure that the power supply of the switch and the module is always supplied, then check whether each module is plugged in the correct position, and finally check whether the cable connecting the module is normal. The solution to such faults can only be to contact the relevant suppliers for replacement.