I've had this problem for a while and plugging my keyboard into one of the USB ports fixes this, but that's not really what I want. When I have my USB hard drive connected on boot (with no keyboard) it halts on the POST. I haven't researched this too much lately, but I wanted to see if people had ideas...
Re-do fabrication of screen [DONE]
Add mini-USB and micro-USB power from M2-ATX [DONE]
Teardown PC [100%]
Add HDMI > VGA converter [0%]