I am looking at an NB10t-A-101 with all the USB ports unresponsive. Windows device manager shows the USB devices as working. I've removed all and had them redetected, with no improvement.

Listed in USB Controllers in device manager are:

Alcor Micro USB 2.0 Card reader
Generic USB Hub
Intel(R) USB 3.0 eXtensible Host Controller - 0100 (Microsoft)
USB Composite device (x2)
USB Root Hub (xHCI)

I've updated the bios to 1.70, and then set it to boot from usb, but it will not recognise a usb device in any port (USB 3 and 2 are both unresponsive).

None of the ports supply any power.

I've tried to revert to an earlier BIOS but the installer won't let me.

Any ideas?