I have a FreeNas box with a ASRock C2750D4I Mini ITX Server Motherboard that has been running reliable for a year and a half, but after a recent reboot, it does not post or show any video.

This seems like a common problem but all of the other threads are stale:
C2750D4I too long pre BIOS startup time
C2750D4I - IPMI Working - Board itself will not power on
C2750D4I - P1.80 - No POST / video

* PSU: SeaSonic SSP-350SE 300W
* 2x Crucial 8GB DDr3 - 1600 1.35v DR x 8 ECC
* Bios: 0.23.0

I have:
* Removed the all peripherals (including the os, stored on an external USB)
* Removed all ram.
* Reset CMOS by removing batter, plug and holding down reset for 30 seconds and shorting CMOS breaker.
* Tried different monitors and cables.
With the above I'm expecting to at least get into the bios, but I get nothing.

Other notes:
* I can access the IPMI, but I cannot get the java apps to display any information. They display a blank black screen, just like the video.
* I have booted up the board and waited the full seconds before the BMC lights starts blinking but nothing appears on screen.
* Everything powers up (fans, disk, both mobu lights)
* I've learned about the Watchdog fix with Bios 0.30.0 but I'm don't know if this is related.
* I'm within my 3 year warranty window.

ASRock support seems to be active on these boards so hopefully they can help.