Freezing issues with MSI 970A-G43 and AMD FX 8320

Question

Hey all,
I bought my brother a new system a few days ago, but he has had serious issues with the machine crashing ever since.
The machine has had a fresh installation of Windows 7, it has all the latest drivers for both motherboard, sound, chipset and video card (Latest VGA driver tested as well as the latest Beta version)
I thought the problem might be with the VGA card, as the computer would just shut off during 3d Gaming, but it also seems to happen when surfing the internet or doing normal "2d" activities
What happens is the computer will just seemingly shut off, the LED lights on the front of the case, around the dials, start blinking and the only way to get it back up again, is to turn if off at the power supply unit and then turn it back on again.
I'll paste in what my brother sent me (As I live in the UK and can't see the machine crashing myself), he said:
I dunno what the issue is but, last night the comp just shut off in middle of game play on 3 different games, and the lights were flashing, I had to turn complete power off to the power box and back on to restart comp, I kept checking all my temps with speccy and speed fan and nothing seemed high at all, also when it shuts off and I re start it, a lot of my desktop icons move around to different spots,
Update: crashed a few times on me, once playing euro, once just browsing Internet 5 min after the first one, changed out ram just for shots and giggles and ran euro on ultra for about 5 min and crashed. I dl a gpu monitor gadget, was accurate on temp but said the gpu was 0% but with just Internet would randomly jump to 99% or 40% then back to 0 and would stay and eventually crash
Spec is:
AMD FX-8320 3.5GHZ EIGHT CORE
500GB SATA III 6GB/S 7200RPM 16MB
COOLERMASTER SEIDON 120M WATER COOLER
4Gb DDR3 / 1600 MHZ MEMORY
MSI 970A-G43 AMD 970 CROSSFIRE AM3+ DDR3 USB 3.0 SATA
CORSAIR 500 WATTS CX500 V2 80 PLUS POWER SUPPLY
ASUS XONAR DG 5.1 CHANNELS PCI XONAR DG SOUND CARD
AMD RADEON 7750 2GB PCI-E
There was a concern I did have when I did search earlier, via a thread on Tomshardware in which a similiar board had issues with the FX8350's wattage going above the stated 125 watts and causing the board to freeze.
It's a different board/chip, but I wonder if the wattage of the CPU goes above 125W and causes problems on the board? Hmm
I feel really guilty right now, because I bought this for him as a present, it was $700ish plus shipping etc and it's been nothing but problems ever since.
I'm going to see what version of Bios he's running when he gets out of bed, but the Live Update software said there were no updates, but I'll have him check manually.
Another issue I noted, was I sent him some ram before the PC arrived, which was:
XMS3 — 8GB Dual Channel DDR3 Memory Kit (CMX8GX3M2A1333C9)
He originally put that ram in with the existing 4gb of ram, so I thought it "Might" be a conflict, due to them having a different Mhz value
So I had him remove the 4gb stick that came with the PC
As soon as he entered the bios, it froze and did so twice
So he removed that ram and put back the original 4gb stick and the bios worked
No idea if the two are related.

Answer 1

I hope this doesn't count as necro-ing a thread (last post was in October), but it's the one closest to my situation.
I have the following setup:
MSI 970a-g43 motherboard
AMD FX-6300 cpu
ATI Radeon HD 4550 graphics card
4x 2GB RAM sticks
2x 500 GB 3.5" SATA hard drives
CoolMax 700W psu
16x r/rw DVD burner
cheapo SD and others card reader that fits in the floppy drive bay
Older PC tower that has a temperature sensor built into it
I built it around November 15th, and it worked until a couple days ago (December 12th I think), when it started doing the sudden shut-off thing. Same as Adresch described: shuts off, tower light blinks, have to flip the i/o switch off and back on to boot again. I consulted a friend for some suggestions, and he said I should put a water cooler in there, because the stock heatsink that comes with most processors are junk. So I went out and bought a Corsair H55 water cooler and installed that.
The computer seemed to run for a bit longer before shutting off. I loaded up the BIOS software, SpeedFan, and HWMonitor. SF said the CPU was running average of 48*C, and GPU was averaging 51*C. The CPU's highest was at 61*C and its lowest was 36*C. BIOS software said CPU was at 35*C the whole time. HWMonitor listed the GPU at 51*C, and the CPU at 7*C. These are all very inconsistent with each other as far as I can tell, so I don't know what to make of these readings. Didn't seem to much matter as the computer continued shutting off.
My options then being replacing the PSU or the motherboard, I decided to replace the power supply, since I was just within the 30 days. Switched for a ThermalTake TR2 700W. Before installing it, I pulled the tower's CPU temperature sensor wire from between the water cooler heatsink and the CPU, just in case. Then I installed the PSU, checked and rechecked all of the connections, and turned it on.
Nothing.
I then spent the next two hours rechecking everything, even unplugging everything and putting it back together. Still nothing. The best I could get was a flicker of the tower light and the fans doing a quarter turn before ceasing movement. The red LED on the front of the SD card reader stayed on the entire time, though, so I guess it was getting at least a trickle of power. I also removed everything but the PSU, motherboard, CPU, and one stick of RAM. Still no power. I think the new PSU may have been open box, so I'm returning it today for a different one, and even bumping it up to 850W.
I'm not sure that will solve my original issue though, so I'll be looking for a heatsink to put on the VRMS as mentioned. Just thought I'd get this down in a relevant thread in case anyone had other thoughts on what could be going on.