Thought I'd cheat and take a picture of the BSOD, second time I remembered to turn off the auto flash.
Full stop code: 0x000000FE (0X0000000000000008, 0X0000000000000006, 0X0000000000000006,0XFFFFFA80083CCB20)and at the top BUGCODE_USB_DRIVER.
The failure happens if in windows I try to use any USB device (which is never detected or works) and then when I shutdown the shutting down screen stays on the screen for several minutes, then the BSOD, then the restart. If I don't try to use any USB ports, or have no devices plugged in then I get a normal shutdown.
I suspect my enable Legacy USB Devices is not enabled, but I did manage through various Heath Robinson attachments to get BIOS F9E installed through QFlash which made no difference to my problem, but only updated my earlier post and the information was not obvious.
Updating/reinstalling all my USB drivers was the first thing attempted, and several times since. At the moment all my USB header cables are unplugged and I am trying to get only the onboard ports at the back working.
I also added to my earlier post that
Unless there are any more suggestions I guess I'll just have to accept that my m/b is somehow hosed and start planning a successor. I'd love to know exactly what has been broken and how, and just not reboot while charging a phone in future.
I'm open to suggestions as to what to replace with, I would like 2 PS/2 ports for KVM reasons but it seems that this is not possible any more with Gigabyte.
Thanks for the help so far, and any more if it comes.
Regards & Merry Christmas again.
Now the creature stirring in this house is still not the lunatic shouting at his mouse