What happened?
The Original Prusa MMU3, and MMU2S are equipped with a control board containing Trinamic (TMC) drivers to manage the motion from each of the connected motors.
With firmware 3.0.0 or higher, in case a short circuit is detected on the Idler TMC driver, the printer will show the message "Short circuit on the Idler TMC driver. Check the wiring and connectors. If the issue persists contact support".
Error name: TMC driver shorted
Error code: #04324
How to fix it?
Access the MMU control board, and inspect it visually to spot any incorrect assembly, or damage on its surface, on the cables, and attempt reseating the cables to ensure their connection. In particular, make sure that the PD-board add-on is attached to the control board.
If the issue is not solved with these checks, please contact our customer support.