I think I may have found the source of the problem. While I had the web interface working I did home the axes. This left my Z endstop triggered which is pulling V to GND constantly it looks like. I'll have to fix this in the morning.

I am able to communicate if I disconnect the Z endstop. I may have to re-design my endstops to use all 3 pins? Or maybe I just have them configured wrong…

EDIT: I just saw your post. Yes, it does look like the same issue.

Additionally, the 3.3V LED is not on. If the 3V3 rail is bad, that would explain why I can't communicate to it at all. Is there a way to repair this? I still don't even know how this could have happened, I never connected/disconnected anything.

I just got my Duet WiFi and set it up with USB for the first time and was able to successfully get the web interface to load. After making a change in the config.g file over the web interface to change it from a delta type to a cartesian printer and pressing apply something went wrong. I'm not sure if I made an improper change in the file or what happened. However, now I can't even access the duet from either the web interface, nor via USB connection (using repetier to try to connect). Looking in Device Manger I don't see the duet either. I have tried depowering and repowering the duet and USB cable as well.

Is there a way I can move back to square zero and start over? Is this just a problem with the files on the SD card? and is there a way I can re-initialize the SD card files?

I'm not very familiar with the duet and am not sure where to start right now.