So i just finished installing this board last night and everything so far seems to be running smoothly except that when restarting, which you often frequently do when doing installing drivers and such, my computer seems to restart, but then never fully cycles. It just stays on like it's running but monitors go dim like it's restarting. I noticed whenever this happens I get a FF error code on mobo but since that's just a basically "something went wrong" and nothing specific, I don't know what to do.

CPU: i5 4690k DC edition
RAM: G-Skill 8gb 2400ghz 
Graphics: Radeon HD 6870 1gb
SSD: Kingston 240gb
Mobo: z87 stinger mini itx
HDD: 1tb WD 7200 RPM Black Edition
PSU: Thermaltake toughpower XT 775w

I'm havig the same problem with the same mobo, same CPU, and otherwise very similar hardware.

Updating to bios 1.09 fixed it for me. This may be a coincidence: i don't see anything in the 1.09 changelog regarding reboots.

FF Post code is a code you never want to see, most propabbly a Bios chip,
FF code came after trying enabling memory XMP Profile ? reseat your mem sticks,
even try to boot with no memmory at all, the 55 code is what you expect
to see,which is good news meaning Bios is alive, check your power supply? Do your funs running?
check all cables, replace or
check mobo's battery,reseat CPU, and check the socket pins, it is common having a pin bented during
installation.Finally contact the EVGA Tech Support.