Right extruder motor spinning backwards

[xchrisd]

I think I remember a similar case where the controller was defective.

Did you try a new cable?

In the meantime, maybe it’s possible to reroot the toolhead port, have a look at M1029:
https://snapmaker.github.io/Documentation/gcode/M1029

A350 3D module not detected, even after new purchase of module

Ah, stupid me, did not read the doc properly. If you go to the page I linked earlier, it is pretty clear. Here’s how it really goes: Start Luban, connect to printer Switch to the “Workspace” section of Luban In the Console section where there’s “Send command”, type M1029 E2 (case matters, captial M, capital E) and hit enter Send M500 command to save setting Power-cycle the machine → Now the setting should stick and the port re-mapping is effective. It will stay until you repeat the procedure…

What happens if you try the single extruder?

Filament motor not rotating (but not physically broken)

I guess support ticket or a new controller is needed. Maybe this helps you at further testing: