BSoD/Complete Shut Downs, Minidump That makes no sense inside

[TheTalon]

So lately I've been having these complete system crashes. Usually the entire PC shuts itself off completely and needs to be unplugged/PSU Switch flipped before it'll cut on again. Sometimes it'll BSoD. The Crashdump says this for every crash (14 total since I've had it over 2 years) for every crash :

This was probably caused by the following module: ntoskrnl.exe (nt+0x4A5E4C)
Bugcheck code: 0x124 (0x0, 0xFFFFFA80048E68F8, 0x0, 0x0)
Error: WHEA_UNCORRECTABLE_ERROR
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
Bug check description: This bug check indicates that a fatal hardware error has occurred. This bug check uses the error data that is provided by the Windows Hardware Error Architecture (WHEA).
This is likely to be caused by a hardware problem problem. This problem might be caused by a thermal issue.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.

I've monitored the temperatures and they're probably below the average if anything. 34C on the CPU Idle, 36C on the Video card Idle, CPU never hits above 55C and the GPU never hits 80C. The voltages for the PSU all seem to be just fine. I ran Prime95 and that didn't crash my PC, though it did tax the CPU hard enough to hit 61C, and I ran Memtest and had no errors with my RAM. I've tried different display drivers, as well. I'm not exactly sure how to approach this problem as nothing seems to be wrong. Any ideas? So far it's only happened while gaming.

From my last BSoD, the event viewer says this:

A fatal hardware error has occurred.

Component: AMD Northbridge
Error Source: Machine Check Exception
Error Type: HyperTransport Watchdog Timeout Error
Processor ID: 0

Bugcheck ID for the crash (And even the crashes the caused complete shut downs) is: 0x00000124

[Warship]

If it seems to be off but can't turn on again before you unplug it completely, it sounds like a PSU problem.

[Killervalon]

Yeah, it's a internal error in the motherboard (as it looks) which has occoured because of the PSU (I assume)

[VikeeVeekie]

You might want to go to the BIOS, open hardware monitor and upload a photo or more of the voltages. Maybe theres a critical drop in voltages causing the system to become instable and eventually crash.