BSOD/Random Restarts/Complete Instability - Even After Fresh Install (from media) and bios defaults

[egoods]

Hoping I might get some troubleshooting insight. I attempted to start up my rig this afternoon and it froze at the logo (spinning balls).... I've been able to get it to boot, but it's about as stable as a three legged dog. I was slightly overclocking, but using water cooling for the CPU and monitoring temps so I doubt overheating was the source.Here's my specs and some troubleshooting I've done/am doing

• 
  OS is standard Windows 10 Pro X64
  
  Mobo is Asus Maximums Hero VIII
  
  Intel I7-6700k running at 4.4ghz with Corsair H100i (running 4 Nactua fans in push-pull, has been stable for months and months, no temp issues)
  
  GPU is MSI GTX 980TI 6G - Not OC'd, honestly it's been almost criminally under-used (I do some light gaming, and a bit of CAD work, but I've never really pushed the card... shamefully).
  
  Recently upgraded RAM - have already tried swapping back to old RAM. No change
  
  Did full format and fresh install of Windows 10 (used media creator on my laptop to make a bootable USB)
  
  Also recently upgraded SSD from 250gb previous gen Samsung Evo (840... I believe) to 1TB Evo 850... worth noting I bought it from Amazon Warehouse Deals (open box). Used Samsung Migration Software and it ran trouble free for ~1 month before today
  I'm currently using Samsung Migration tools to replicate me 1TB Pro SSD in my Thinkpad, I'm planning to swap the drives and see if the SSD runs stable in my T460P (man I wish this had the old-school Thinkpad one screw drive slots... the 6 or so screws and spudger pry routine always scares me a bit)
  
  Also messed with display drivers/used DDU in safe mode to remove drivers/tried installing older drivers thinking this might be contributing to the issue (I've had issues with Nvidia driver updates in the past so it was worth a shot)... also, no dice.

I can't think of any other relevant info... I'd really just like to get some community input/thoughts. I'll report back on how the SSD does in my laptop. If it's stable I'm at a crossroads as to what troubleshooting step I should take next.

UPDATE: Currently typing this on my T460P with the SSD I suspected (hoped...) was bad. It booted without issue and has been running stable for about an hour now. So I'm down to Mobo, CPU, or GPU.... and I think they're the most likely culprit in that order... agree?

 

[Ironsounds]

Hello... 1) Typically when ever you start changing hardware/ram/etc? on the MB you should always do a battery removal and CMOS clear, for new communications settings to be created and stored for these devices. B /

2) The CPU power circuits will get reduced Cooling when there is not a FAN present/used on the CPU cooler... OC'ng the CPU can also increase the temps in that area too. B / give that heatsink a slight touch for investigation.