I thought it would be the board too. I was hoping I could try every option first before I swap it out. I have ordered a bios chip and will replace this as I can't flash it normally. After soldering on a new chip and still no good I will give up on the board.
Hi just picking up on this thread, coincidentally I’ve got the same/ similar problem.
So I upgrade GPU, RAM and CPU. CPU arrived first and went in ok, working fine. Required BIOS flash, all ok. Next day installed RAM and GPU didn’t boot, reset CMOS running ok but really slow. Quick scan said RAM needed BIOS update.
Flashed BIOS again but stupidly clicked on BIOS and ME trying to rush the job! That flash failed and now have motherboard with D0 debug code, on the switchable BIOS mode I have no debug codes (won’t even show digits)
It powers up all components have power just won’t go in to boot.
Looking like a new motherboard, however reading a bit it was mentioned that jumping the JME1 may put the motherboard into recovery mode. Not hopefully, think I’ve actually burnt out the BIOS chip but maybe a cheaper option to try first, it’s not worked under power off, just waiting on some jumpers to arrive.
Prior to upgrading I had to take the case off to identify the motherboard (misplaced the manual) it wouldn’t boot up after that that required a CMOS reset.