About external driver extension

[979044817]

Dueu2 I used the external drive board and 8825 drive extension (E2) (I did 3Z). After working normally for a period of time, I suddenly lost control. When the heater is turned on, the motor will lose control, make loud noise and heat, but the heater is driven normally without turning on. Then I turned off the power, rechecked the lower cable, the motor was normal, and replaced the 8825 drive. The problem remained. When I disconnected the power supply and restarted again, the WiFi light did not light up, and I was told that the main control was broken. I don't even know what's going on? The 12V power supply and the cable of the drive board are also correct. Is there any way to protect the output signal of duet2? Isolation protection（ The above contents are translated by the software. Please forgive me for any incorrect statements)

[dc42]

@979044817 I think you have a bad ground connection somewhere, possibly at the VIN terminal block on the Duet.

[979044817]

@dc42 Could it be a power problem? I am using the IBM server power supply now. The AC220V is not grounded after input. There is a sense of leakage when touching the power supply shell with my hand (there are also hot beds and extruder heating heads)

Thank you for your answer