Happened once a couple days ago, couldn't get it to boot for ~ 24 hours.  Now it's gone again and nothing i've done will get it to wake up and start booting :-(

Tried long-press power,

tried PSU on/off,

tried CMOS reset (button and jumper)

tried battery disconnect,

tried removing all parts,

tried only CPU installed,

tried CPU + mem installed,

tried another PSU

Any tricks i'm missing?

All give the same result, white light on the board, turns to blue after 5 seconds or so, stays that way forever (debug code does not light up, no fans or any other sign of life).

Not sure if this is just a BIOS issue, or a bad board.  It's been fine otherwise :-(

Regardless of your config, the first place to check is power. This should be the first step in diagnosing any failure to POST issue. Reseat all the power connectors and make sure they are seated correctly.

Good luck.

Thanks for the quick reply!

CPU : i9-7980xe

CPU Cooler : Kraken x62

Mem: 32GB Corsair Dominator Platinum

GPU: GTX1070

Storage: Samsung 960 m.2

With all components removed, same result.  Just doesn't want to power up :-(

I've re-seated the power cables (all 3 of them), which didn't help.  Going to switch the cables themselves (modular) just to be sure, though as it runs fine when it does POST, i'm not expecting that to be the issue either.

I assume you have not delidded your CPU? 

First up, try removing the CMOS battery again, ensure that all power to the system is pulled and press the power button for ~5 seconds or so to discharge the capacitors on the board. Seeing as you are going to be changing the PSU cables do this while they are disconnected from the system. Leave the system in this state for at least 1 hour before connecting everything up again. If this does not bring the system back then its time to dig deeper.

The fact that this is not the first time this has happened it is somewhat concerning. Do you run the system through a UPS of any kind? It almost sounds like the power protection circuitry on the board has been triggered, this usually only happens when there is some kind of surge or a brown out (high or low mains power).

If the thorough clear CMOS does not work post back and we will have to start looking at more drastic troubleshooting.

Tried the other cable set, board has been off for an hour.  No change.  Tried the initial power on with nothing installed except 3x power.

Powered off again and will retry with the CPU & mem in place. 

I'm not using a UPS, the mains here isn't known to be a problem but i can't rule it out.

Again though, this only occurs once the system has gone to shutdown/sleep, so not sure if a mains issue is likely.

If neither is lit then the only thing left to try is stripping the system down, pulling the board out of the case and bench running it (breadboarding). If at that point you still can't get it to post, it's time to RMA. There are a few other things you could do to troubleshoot/repair the system but with a new board, it is far better to use the warranty and get it replaced. 

As inconvenient as it is, it is preferable for the peace of mind.

I hope it doesn't come to that but at this point, that seems likely 

The board's been out of the case with minimal parts installed since i started the hour long power off (the second attempt didn't work either), so no more luck there.

I'll see about getting it exchanged via the retailer today, only a week old so shouldn't be a problem.  

Thanks for all the help, much appreciated, good to have gone through the options :-) 

Let us know how it goes 

Without CPU installed it wouldn't power up the Debug display (not surprising).  CPU installed and everything went fine.  System back in case, all good.  

Couple reboots later and it's showing the same problem as the first board...  It's managed to restart a few times via power off, CMOS reset and power back on.  At the moment it's refusing to reboot, and i'm letting the power drain :-(

So, likely explanation is something in my setup is incompatible.  A second faulty board seems unlikely (even if from the same batch).  I just don't see what could be doing this, everything is fine if the board would try to POST.

Only additional info, on a couple of occasions after CMOS reset, i'd go into the bios, save and exit, wait for the splash screen to show again then hit the power button to turn everything off. Then the board would stay awake, red led next to the Debug display stays on, until a long power button press.

Not sure that helps any :-(

EDIT:  PC is currently running.  Only way i can get it to boot is by holding the CMOS reset switch with the power on, while it's 'stuck'.  Works maybe 1 in 10 times.  This is a full system inside the case.

Is your SSD 960 EVO and what firmware? Right now SSD firmware update seems the most likely culprit. I don't update firmware too often. I updated it today and after the update system is not posting. Update itself was successful as no errors were displayed.

Latest firmware for 960 EVO came sometime beginning of November I think.

i have i7 7820x

4 Hyper X Fury 16 GB DDR4 2400

i tried gtx 580 and gtx 980ti.. same problem

and kingstone SA1000M8 M.2

Aerocool 1000W ups

my board lights is on, but cant boot up. always no signal on screen, and getting A2 error, even if i have no sata instaled..