This is a system that I've had running earlier in the year with these same components but now it won't boot.
The CPU fan spins up for a few seconds, then the system shuts down and tries to boot again. I get no display on my monitor (via DVI using the onboard video, or with a discrete graphics card). I've eliminated all unnecessary peripherals. I have tried clearing the CMOS and re-seating RAM and SSD, but it doesn't have a place to connect a PC speaker to give me POST codes.

Does anyone know how to get some useful troubleshooting data out of this thing? I'm an experienced system builder but it just isn't giving me much to work with.

Specs
Motherboard: GA-B85N-WIFI (miniITX)
CPU: Intel 4130T
RAM: 8gb Samsung DDR3 1333
SSD: Crucial m500 mSATA
PSU: 150w picoPSU
Video: Onboard Intel HD Graphics - OR - AMD HD7750