Have you tried making a new config with the online configurator ? https://configurator.reprapfirmware.org/

Did you follow this for connecting and setting up your endstops? https://duet3d.com/wiki/Connecting_endstop_switches

Watch the video and check you wiring on the steppers https://www.youtube.com/watch?v=S0pGKgos498

Have you check that you have the stepper motor wire connected correctly? in the correct coil pairs

Do you mean that the steppers are turning the wrong direction or rotation? or just not working at all

Just run a bunch of G30 S-1 commands where you plan on probing the bed and see if they come back consistently the same or very close from each probe like within 0.01 of each other. Wile I don't print on my aluminum bed bare I did probe it a lot when building my printer and the ir seemed to work fine with it

What surface are you going to print on? Just the bare aluminum or glass or PEI?

I did the modification on one of my Duet's and it did improve my signal strength but there are easier ways to do that than possibly ruining the control board. I would not recommend this mod for the novice or faint of heart. It can go really well or really bad in the space of a few seconds. But if you still want to do it one thing that wasn't mentioned is that you will have to load the wifiserver bin on to the new wifi module once you solder it on via USB and SD card using an M997 S1 command or at least thats how I got mine to work.

https://duet3d.com/wiki/Getting_connected_to_the_Duet_WiFi

@dc42:

What error screen?

Sorry should have specfic
The blue box in the camera feed box with the temp error.
Sliced in KISS using the same profile that I usually use and haven't seen this behavior before where it keeps on flashing every few seconds, but I'll check the slicer profile again to see if I changed anything