So, full admission this is the third time I've had to make a thread for this issue. Past threads have been locked or something similar to prevent replies with no actual solution to the problems, so a lot of this OP will be cut and paste. Anyways, Ever since I built this computer in August last year, I've been having  random and unpredictable computer crashes. They aren't blue screens, but it's still an issue because it forces a reboot to get out of the crash, and that causes issues with other things that I deal with, such as internet caches dumping themselves every time, and graphical settings being reset. The actual error message is:

A fatal hardware error has occurred.

Component: AMD Northbridge

Error Source: Machine Check Exception

Error Type: HyperTransport Watchdog Timeout Error

Processor APIC ID: 0

I've been trying to solve or get help with this for months upon months but nobody seems to know what the actual cause is. Google searches show that this has been a recurring problem for AMD users since Windows Vista, and to this day there is no solution. I've tried multiple suggestions both from users here, as well as many other help related forums, but none have worked. To date, I have tried:

Updating Drivers: didn't work (Drivers were already fully updated)

Uninstalling and reinstalling all drivers and chipsets fresh: didn't work.

Removing and re-seating the GPU: didn't work.

Using many different power outlets in case the power was dirty: didn't work.

Cleaned out the entire inside of the machine: didn't work.

Multiple different fan settings and orientations to disperse heat differently: didn't work

Stress tests and mem tests: didn't work. (Everything came back as working fine)

Sfc /scannow, chkdsk c: /F /B /X, DISM /Online /Cleanup-image /RestoreHealth, DISM /Online /Cleanup-image /AnalyzeComponentStore, ran DDU in Safe Mode, none of these worked.

The only thing I can even think of left is a Hardware issue, but there have been so many different claims of cause that I wouldn't know where to start. Bad PSU, GPU, CPU, Montherboard, Memory, pretty much everything. What's more, I have zero funds to go about just replacing parts on a whim, so if I'm going to replace a part, I need more info to be certain that I'm fixing the right part. The closest thing to "likely" that I've considered as a purchase is the PSU, since mine runs unusually hot for some undetermined reason (127*C at its recorded hottest, but it's constantly fluctuating between 50-110 on HWMonitor), while the GPU and CPU are running within acceptable temperatures.

My machine specs are:

Radeon R9 270X GPU

ASRock 980DE3/U3S3 ATX AM3+ Motherboard

AMD FX-4350 4.2GHz Quad-Core Processor

16G of Memory

600W Power Supply

Windows 8.1