i had exactly the same problem with one hex16b - in my case i used same PSU, PC and miner all in one case, running fine for weeks but suddenly - usb ports dead (all on the board), miner dead also (only fan is running). Changing the mainborad was no problem, warranty and was done between 3 days, but the miner...lol... you see how technobit communicates with customers...

never ever!

btw, anybody wants to by this thing?