I'm already coming at this from the point of 'I'm probably pinched', but I thought it would be worth a try:
My DX58SO is running on tired legs and it looks like I've lost USB support for my keyboard and mouse. I was unable to detect the mouse booting into the OS (Win7Pro) and could get the keyboard at the user account selection screen, so I was trying to salvage some stuff using a RDC from my laptop. It's not a big loss as I've got a backup, but there's still a few things that I'd like to be able to access if I can.
I had a lock up and failure and I'm getting the screen telling me 'the BIOS has detected unsuccessful POST attempt(s)'. Because the keyboard isn't detected at this stage, I can't select 'Y' or 'N' to move off this screen.
Changing USB ports from front to back panel or into different ports on the back panel gives me no love. However, there are two ports that mean I can't even get to the screen I mention in the paragraph above, but I don't know what that's about. They're the two top USB ports on the back panel (so the USB 3.0 ports, I think, but I'm not certain) and they delay the arrival at said screen until the USB keyboard is unplugged.
Getting another keyboard and a mouse is, strangely, a hassle, but could be possible for testing purposes, but I think it's a deeper problem then that.
So, if I can force my way past my block without a keyboard, I'd love to know about it.
McPhill, I am sorry to hear you are having problems but let me help you. I would need to get some additional information, so please let me know:
Let me know the results.