@droftarts well I've tried 3 usb cables so far, but we use usb cables in the product we manufacture so I have a few hundred more I could pull from to test.
I'm on arch linux.
windows is not available to me for testing
I have already followed the duet wont respond guide
Duet 3 MB6HC: There should be a red LED illuminated between the USB connector and SD card socket. The red 5V LED at the edge of the board should also be lit, so should the green 3.3V LED.
the 5v and 3.3v are lit
The DIAG LED may or may not be lit, but can help diagnosis:
Duet 3 MB6HC: DIAG LED is between the reset switch and the SD card socket
I don't have a diag led. I have a status led. it is just barely dimly lit. before erasing the firmware it was brightly lit.
the image flasher steps assume raspberry pi use. while we do have a few thousand pi 3 and pi4s in stock, I wasn't planning on using a pi with this setup.
I have already gone through hte steps for standalone mode formatting. first of all the official "sd card formatting tool" is a broken link. so that can't be used. secondly I really don't understand why I can't use a normal tool like gparted.
I have tried reformatting the sd card and filling it with firmware, sys, and www directories. it's not clear if anything more is needed.
I'll post an image momentarily but it looks fine