Computer freezing with a black screen(still back-lit)

Hello, I’m looking for some help with my rig which is keeping me rather confused. The computer will randomly freeze, go to a black screen and lock up. The confusing part is it only does this when there practically no load on the system. It will play games maxed out all day long but when I come off and try to load up a browser, it just crashes. I will need to hard reset the computer at this point, but when the computers starts again it usually turns all my fans on full and wont display anything on the screen. Or it will stop loading and present me with an error 62 (Dr Debug on an Asrock Z97 extreme6) to which seems to be a RAM issue of some sort as I keep finding forms saying to pull out the RAM and reset the CMOS, or set XMP profiles, which doesn’t help. Also tried 3 different sets of RAM with this issue persisting. The other thing about this is that it has persisted through a complete rebuild of my rig, with only the SSD/HDD and GPU staying the same.
Mobo: Asrock Z97 Extreme6
CPU: i5 4690k
RAM: 16GB HyperX fury
GPU: Sapphire 290 vaporX
PSU: EVGA supernova 850W 80+ gold
SSD: OCZ arc 100
HDD: 1TB Seagate barracuda
Windows 10
The issue really has me stumped at this point as any issue I can think of would affect it more when the computer is under load, not when it sitting on the desktop doing nothing.
Sorry that this probably reads badly, I’m terrible at trying to explain things.
Also thanks in advance for any help anyone can give.

The error code seems to be related to southbridge devices. WTF is that you might ask...
You can see from the diagram on the wikipedia page that the southbridge mainly deals with legacy devices, such as PCI, IDE, and USB devices. Others are listed there as well.

You can also see that RAM and PCI-Express devices don't connect through the Southbridge.

Are there any legacy devices attached to your system?

Can you confirm the error code is in fact 62, and not b2?

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As far as legacy devices go I don't believe I have any, maby my keyboard that's just a basic one I got with a computer a few years ago but I think everythings modern, and the debug looks to be b2 rather than62 now that you mention it. And I forgot to say that all the issues started around the time I installed the 290, could just be coincidence though, originally I just thought it was the gigabyte motherboard could hold the correct voltage for the card, hence the rebuild. And with the card being one of the 2 parts that I kept keeps me thinking it's the card somehow.

it has come to my attention that my mouse may be the issue, iv got a steel series diablo 3 mouse (pretty much a sensie if i remember correctly) that the drivers can cause the computer to crash, only thing is if that was the cause why doesn't it crash when playing games. If the computer would crash at just any time this whole thing would just make more sense to me.

After changing the mouse and using the for a while, that definetly wasn't the issue.

Did you allready tried a bios update?

No, I haven't but I'll give that a try