Hi, I am trying to flash a couple used Bitmain Antminer S9's over to BraiinsOS+. However, I'm hitting a road block.

When I set J4 to boot from SD card and insert an SD card flashed with BraiinsOS+ the unit does not boot properly. After about a minute I get a solid red status LED and the control board doesn't request an IP address from the router.

I have been able to reset the stock antminer OS that is installed on NAND and can get to the web interface now if it is set to boot from NAND. Antminer is running the latest 2019 firmware I think so SSH is disabled.

At this point I think I need to dust off my USB to serial converter and tie into the serial port on the control board to try and see what is going on.

Does anyone have tips or troubleshooting steps that I might try?