All I can really think of is that your system doesn't like the high CPU/DRAM clocks (although they aren't that high...) Maybe try rolling back memory to JEDEC 2133, see if you still get the problem. Or rolling back the CPU to stock and see if you still get the issue. If either of those solve it you can rule out either of the other.
There was also a BIOS patch on 19/01/2016, not sure if that'll help - worth giving it a go.
With XMP memory issues I've heard that this sometimes fixes things:
CLK Rising slope and CLK falling slope both to 4, under Extreme Tweaker > Timing Control > Skew Control
The strange thing is that after I got rid of the Q-Code 13 upon its very first boot after I built it it worked fine since late November with said overclocks until 1 January, which gave me 25 (= nothing), 14/15 afterwards/after CLR_CMOS.
I have run the system without any OC or XMP for a week and the issue persisted as usual.
Yeah I plan on flashing 1402 a.s.a.p. - however I fear it might shutdown in the midst of it since it already did once while looking around in the BIOS; that would ruin my BIOS I imagine.
I plan on not using XMP but setting it manually; is setting the CLK slopes still beneficial in that case?
Get us some screenshots posted of the BIOS dude
From what Ive read its time to go full manual.
It is strange how so many can just put it together and it works without much tweaking - if any at all - and mine won't, and I don't have anything too fancy either.
Would it also help if I provide a brief overview of the issue? There's so much info in the thread I linked it's rather chaotic now. I can make it concise.
I'll do the screenies first before I attempt anything else (except flashing the BIOS), and take it from there. Thanks to both of you for getting involved - much appreciated!
EDIT 24 January:
Shop said surges are the issue in the PSU.
I will Tom, thanks. F12 I believe? Any particular sections you would like to see in the BIOS screenshots? And with what profile loaded? Right now it's on optimised defaults (on which it also shut down previously).
Updated the BIOS yesterday to 1402, because it's there, and loaded optimised defaults. Didn't do much else but thought I'd run 4 instances of HCI Memtest overnight, each of 1750, coverage this morning was 1480+ % with 0 errors. Task manager said it loaded up 8GB of 16, that doesn't like the best coverage of the total RAM?
I did make pics of the socket and CPU from all sides since I had it out.
http://i64.tinypic.com/2lthtvt.jpg
http://i64.tinypic.com/2pyxpmp.jpg
http://i64.tinypic.com/jb1l3r.jpg
http://i65.tinypic.com/2ds30it.jpg
http://i64.tinypic.com/282okno.jpg
On a side note, tried to disable Thunderbolt and I can but is also enables some sort of native PCI setting? Is that okay, and, what is it?