I wanted to start off by saying that I have already done a ton of searching and am no closer to a solution.
I have a Gigabyte Z170N Gaming 5 ITX motherboard, 6700k, 16g EVGA ram and a Samsung 850 Evo m.2 drive. Last Winter I built the system, remember going through some issues to install win10 and ultimately have been running fine for months. Recently I was looking into PWM case fan control and noticed it wasn't available on my BIOS version (f3) and remember noting that it was strange I couldn't see my m.2 drive but didn't think anything of it as everything worked fine.
I just moved the system to a new case and upon booting for the first time, I couldn't get out of the BIOS. I couldn't see any bootable devices at all and was stuck. Reseated the drive a few times with no luck and went through lots of changes in the BIOS all without any effect. I then updated to the most recent BIOS (f21) and same issue.
All posts online show trouble with initial install, not something like this. Any ideas? I'm baffled because everything worked fine and not I just can't boot. The only hardware change was the video card using a riser card (any chance that effects this)? I didn't even remove the ram or the m.2 SSD but I have since re-seated several times.
