A10-7700K PC hanging

About two or three years ago I built an APU PC with the following specs:
- AMD A10 7700K
- 1866MHz RAM (corsair vengence)
- Asus A88XM-PLUS Motherboard
- WD Blue 1 TB HDD
- Corsair CX600M PSU
- Fairly generic Corsair case

The Mobo, CPU and RAM were all bundled together and pre-installed so out of the box I only had to screw it in and attach all the relevant cables (just because it was easier and shipping is expensive in the UK).
Link to item : http://www.maplin.co.uk/p/aftershock-quad-core-amd-fm2-35-ghz-8gb-motherboard-and-processor-bundle-a94nj

One issue I did have at the time was where to plug the fans in, and I ended up with the rear, cpu and one front fan being the only fans I installed, the rest never being used.

During the first year of using it, occasionally the PC would randomly power down (I was using Ubuntu at the time, if it matters), although I figured that it was the 664 pin mobo power cable being loosely fit, which it was, as I could fix this by pushing on it to go back in, and then hitting power. I might not have installed it properly from the beginning, as I was scared of breaking the Mobo.
This issue went away after a while.

I upgraded to Win 8 and started using it more intensely, and there were no issues for a while.

About ~3-4 months ago I moved into a tighter space (and upgraded to Win 10) and it was a very tight fit with my computer and chair. Occasionally I would knock the computer, if not that violently, and about 2 months ago the computer would suddenly reboot, with a screen before loading windows and after the prompt to open bios of something like "Automatic reboot due to power surge".

One night, at the start of last month, I knocked my computer during an intense session (Skype, CSGO and someother programs running). It rebooted with the same "power surge" message before windows loaded, all the programs open began to load again, and about 2mins in, the computer froze, and the previously very loud sound of the hard drive stopped; after nothing moved (no loading icons or mouse movement or colour change) and a wait of a few minutes I restarted, and encountered the same problem, and again and again and again. I assumed It was due to a long session, and left it to cool overnight.

Here's what Ive done to try and troubleshoot the problem:
- Using the Advanced troubleshooting options (refresh and restore points; both hung mid process)
- Airing the PC out with canned air
- Reinstalling Windows (from USB) several times
- CHKDSK and CHKDSK /r /f /x (hung mid-process)
- Installing a new Harddrive with a new sata cable (note: I havent tried every sata port on the Mobo yet)
- Using WD repair utility (hung once but then also fully finished an extended test with a pass)

Any help is appreciated and I will remove this if asked.

I would attempt to flash the bios of the motherboard as the next step. This could solve the problem but probably not. By the sounds of what you describe here some kind of damage has occured. I would isolate all the parts in other systems to test them. Find the culprit. Think of an operating system as a house of cards, if one of those cards is bent wrong the whole thing won't stand up.
Do you have another computer that you can put individual parts into to test their functionality?

Why would you keep your PC in a place where it could be constantly hit?

otherwise, maybe buy a new motherboard, probably something ITX and keep your PC away from your feet.

I had a desk ~90 cm wide and that was it. the monitor is 24" so the case wouldnt fit on the desk properly. I had to put it underneath the desk, which made it a very tight fit with my chair. Thanks for responding.

I dont have a way of testing all of the parts (ie different system components lying about) bc this was my first build. Its currently at a repair place being "diagnosed" but what Ill most likely do is buy a new motherboard. Thanks.

this was resoved by sending it to a repair shop. yes, it was the bios, and i shouldve flashed them. did i? no

I'm glad it is fixed. I hate when I have a problem and can't figure it out.