Computer crashing, have tried almost everything!

[SMNaCarbie]

Hello FFXIV Community!

I am the resident go to guy when it comes to everything computers with my family and friends, as I'm sure many of you reading this are, but I'm semi-stumped on my friends current problem.

First, I want to state that it is NOT FFXIV specific, it also happens in other games (such as Diablo III) and even sometimes when she has multiple websites open (like a youtube video or two, chatting on fb, etc.)

Basically the computer just shuts off. No blue screen, no warning, just shuts completely down. On FFXIV, it was happening about every 15-30 minutes, on other games every 45 minutes to an hour and a half. To save time, here's what we've already done/tried:

• New case (old one was horrible at airflow)
• Memcheck, 1 piece had an error, taking out that piece did nothing to improve it.
• new PSU, didn't help
• Changed video card to a much lower end card. This helped, making the crashes happen every hour instead of every half hour.
• Changed the Heatsync by request of someone at BestBuy. I wasn't there, but something about it possibly being broke. This helped the most, but the crash still comes every couple hours.

Now everything points to a overheating, which is why my first instinct was the video card, but as it sits, the only things we haven't really touched are the processor and motherboard. She's low on money and can't afford to replace both (or maybe any at this point), so finding out which one it is would really help her (and me, I've been dealing with her computer for too long now...), her specs are as follows:

• Windows 7
• AMD FX-6100
• 8GB DDR 3 RAM
• MSI 890FXA-GD65 (MS-7640) Motherboard
• AMD Radeon 6700 series (I think it's the 6750, but not 100% sure, also not sure what the low end card she is using is)

Thanks for any help.