It almost seems to me that the controller board on this unit is defective. This has been going on for over a day now.
The controller boards reeeeally rarely fail, its much more likely to be the SD card. Try reflashing the SD card with the image in post #2 (or clone your other unit). If that doesn't help then we're on to searching for the hardware cause.
Not to double post about my current issue, but I never see a light at all around the controller board or the Lan port, or really anywehere except the ones by the pushbutton on the PSU where I see the flashing red and steady yellow.
Is this PS related or should I try flashing.
What software to write the image to the SD card, I have a card reader.
Flashing red + yellow means faulty, PM BitmainWarranty to arrange an RMA. Be sure to link to your post describing the issues, what type and how many miners you wish to have repaired/replaced and your bitmaintech.com order number.