Freezing and posting issue, made apparently worse by new water cooler.

[Tysidious]

Bought the computer a few years ago, and right out of the box, it would randomly freeze.
Replaced the GPU, still would freeze at random times under medium to high loads.
Replaced the MOBO, no luck.
So I disabled two of the cores and doubled the fans. Seemed to help, but did not solve the issue. The CPU idled at 35-40c

Fast forward to the present:

I want my two cores back so I buy a Corsair H100i V2 water cooler.

Now all the computer fans, lights, and cooler power on. But the computer will either struggle to post, sometimes taking minutes to do so. if it does as all. Sometimes it just shuts off within 10 seconds of being turned on. And if it does manage to post it will freeze anytime whilst or after it is loading windows. If I make it all the way to the desktop, it will freeze within 5-10 minutes, just idling. During that time averaging 18°c

I've tested the RAM, they are fine.
I reset the CMOS, no change.
Tried a brand new PSU, still performed as detailed above.

The only obvious thing I havent tried is putting the heatsink back in, because I cant understand how a CPU Cooler could effect posting/booting.

Thoughts? Did I damage the MOBO installing the cooler? is it software/os related? Has it just been a bad CPU this whole time, even so, why the boot issues now?

Thanks for your inputs! I'd appreciate if we kept the brand bashing to a minimum.

Thanks!

MB: Gigabyte 990fxa-ud3
GBU: MSI 970
CPU: AMD 9590 8CORE 4.71
COOLER: Corsair h100i V2
PSU: 800w
RAM: 16 GIGS

 

[vMax]

This looks like a deeper problem that the corsair AIO... And the fact you have been living with half a CPU! Hopefully others can help diagnose the issues but if you have not done this, then I would start at the beginning and go into BIOS and load opttimised defaults and then a clean install of Windows 10...