Faulty mobo?

[BMCappelletti]

Hi, everyone.

 

First, here are my computer basic specs:

Asrock X99M Fatality Killer

Intel Core i7 5820K

16GB DDR4 2400MHz GSkill

Gigabyte GTX 1070 Gaming G1

Samsung 960 EVO 500GB NVMe

 

About a month ago I tried to turn on my computer and fans started to spin, LEDs flashed and all turned off. Then it auto tried to start again, over and over, with no success. I had to turn the PSU off, so it stops.

I tried unplugging stuff to check for some faulty accessory and the computer booted up when I removed an USB 3.0 adapter. Until yesterday everything was working fine. But now the problem is back again.

Once again, I disconnected everything, but the problem persisted.

Tested my EVGA PSU with the included test bridge it comes with. Seems to be working fine.

By this time I was already turning it on using the onboard mobo power button, to make sure the case front panel was not the problem.

Changed BIOS from A to B, on the onboard switch. Nothing.

Turned PSU off, waited some seconds and reset CMOS using the back panel button. Turned PSU on. It booted up! Directly to UEFI, of course. Just hit F10, to save and reboot. I was back in Windows. Relief.

Turned the computer off. Turned it on again, no boot. Same initial spin on fans and turning off. Auto trying to turn on again. Same thing as before. It was late, so I went to bed.

Today I decided to test with just one stick of RAM. No boot. PSU off, cleared CMOS, boot to UEFI, save and reboot. No luck. Tried another stick of RAM, same steps, now it worked. I was on Windows. So then I was believing the problem could be that stick of RAM. Tried another one, on another slot, no luck. Tried some combinations, no luck. It seems random.

Now everything makes me believe I have a faulty motherboard.

Any clue? Any other thing I can test? I was on UEFI revision 3.40 and now I'm on 3.50 (latest).

I don't have another X99 computer here. All I can try is the PSU from another PC. A 1156 build. So nothing is compatible.

Any reply is very welcome.