If hash board 1 works fine for a while after a reboot and then it stops it's highly unlikely to be a software/firmware issue, it's either getting too hot due to a loose heatsink or something blocking the airflowg, or it simply is dying.

It could also be a PSU problem, to troubleshoot that, unplug one of the other hash boards and see if hash board 1 keeps mining, also since this is a rare gear and they have no official website to download the firmware from, you will need to get it from random links such as this one