inZaniac

Don't, reinstall is the last thing you wanna do, check the hardware first:
- Memory : unplug, clean and check with Memtest86.
- HDD: scan and repair. check for bad sectors.
- Check temperature, if hot, clean heatsink and reapply thermal paste.
If everything clear, now open windows update, uninstall the last / recent update.

Hey guys,
 
a few days ago I turned my PC off for the night since I was not going to use it for a full 24 hour period and this was after I had left it on for weeks with no problems. When I went to go turn it back on, it started up just fine and then about 15 minutes later it died. Lost power completely. I looked into and did a couple of things, basic troubleshooting things if you will and got it back up and running. Started playing some games (Dying Light Enhanced Edition) with a friend and about a couple of hours later, it just lost all power and shut itself off again with no chance of revival it seemed. Took it down to my grandmothers since I would be spending the weekend at her place and brought my old power supply. Went through, re seated everything and it was trying to come back to life, but it was a continuous power on and off like it was trying to get going but just didn't seem capable of it. So I switched power supplies (the first one being a 750W EVGA B2 80 cert bronze and the second one being an OCZ 600W 80 cert PSU) and still nothing, a couple of lights turned on and then nothing. Then I decided to take everything out except the CPU, a couple sticks of RAM, and the mSATA SSD that is stuck to the board because I don't have the screw driver to take it out (Where is that iFix it kit Linus always uses lol) and still nothing. 
 
TL;DR I think the MOBO is done (MSI Z87-GD65) and I need a new Motherboard. That being said, stores don't really carry LGA 1150 socket motherboard now so I am in the market for some new RAM, a new CPU, and a new MOBO but don't quite know what to get when it comes to the board. Any suggestions on what to look for would be greatly appreciated.
 
also, if anyone could explain what or why this happened, that would be very useful to know and on another side note, the 750W psu is only a few months old because I was experiencing similar problems late last year until I brought it to a friends house and they swapped PSU's and it seemed to have worked. This has been an ongoing issue that I thought originally was a PSU problem but that is not the case anymore. 
 
For those who want to know my old specs:
 
CPU - Intel i7 4770k
Graphics - EVGA GTX 970 FTW
RAM: 2x Hyperx and 2x Kingston 4GB sticks of 1333MHz
MOBO (dead I think) - MSI Z87 GD65
PSU - EVGA 750W B2 80 plus bronze.
 
Thanks guys.

Quick guide:
Put voltage on manual, I suggest 1.15v as a starting point. Leave the frequency at stock. Stress test with Prime95 Small FFT for about 5min. If max temp is: Below 81C, increase voltage a notch and repeat step 2 Between 81~83, move on. Above 83, reduce voltage a notch and repeat setp 2. Once you've found your max voltage, start increasing core frequency. Stress for about 1h, until you've found instability; at that point, back off to the previous value. Once you've got that, go for a lengthier 8~24h test. If stable, congrats, you've got your OC. Otherwise, knock the multiplier down a little.

Get a cooler (whether a 240mm AIO or a just a tower cooler). And then OC it manually. Really, that's all there is to it.
Aside for OCing the CPU, OCing the RAM. And the GPU. Those are the easiest of things you can do to get free performance.