Which hardware is failing?

What component should I replace?

My home build PC is acting up. I'd like to only have to replace what is obviously broken. I was getting blue screens like this.

From three days ago.

WHEA-Logger:

A fatal hardware error has occurred.

Reported by component: Processor Core Error Source: Machine Check Exception Error Type: Cache Hierarchy Error Processor ID: 0

Then it wouldn't stay powered on for more than a few minutes. Like the MB just does a forced shutdown without telling the OS. I think it was so hot even the bios would lock up.

I tuned the bios to put the fans on duty instead of silent. Now I'm back to the first behavior

From today

The computer has rebooted from a bugcheck. The bugcheck was: 0x00000124 . (0x0000000000000000, 0xfffffa800d93b028, 0x00000000b64a4000, 0x0000000000000175)

SpeedFan reports Temp1 60C when idle. And up to 85C when all cpu's are in use.

Windows7 sp1

AMD Phenom ii x6

Asus crosshair V formula

corsair h60 cooler

32GB ram.

I've tested each stick of ram by itself and I get the same behavior.

The most frustrating part is I left the machine on all day and it's fine. But about twenty minutes into active use. (even if I'm checking speedfan for overuse), It just fails.

It is possible the heatsink got loose and there is a small gap between it and the processor. To fix it you have to remove the heatsink, clean it and apply new thermal paste.

There is no way to be sure if this is the problem in your case, but it's easy and cheap to fix (compared to a new CPU).