Came home from work and it had done it again. It's like the PCIe lanes fail. Took out my GPU, popped it into the other slot and still the same, no display. Put it back again, cleared CMOS, a few more reboots later, it's back. I have rolled back to 0810 BIOS as this was a tad more stable. Hopefully it will stay on overnight and the display will be functional in the morning.
Update: It seems to be getting worse. I was playing Elite Dangerous for about 20 minutes when there was a change in the sound of the GPU fans and low and behold, the display crashes again. I can still her the music and sound but my screen gives the no signal box. As I have reverted the BIOS, the reboot seems to clear the issue until I ran Elite and it crashed again.
Could I have a dodgy board or is it the GPU? The GPU ran perfectly fine until I upgraded the mobo, CPU and ram.