Possible PSU failing after CPU OC test, advice needed.

I'm not sure if this is in the right thread, please have it moved if I put in in the wrong spot. Also, sorry for the wall of text, I wanted to be thorough.

I decided to finally OC my CPU as it was something I was always meaning to do but never got around to it, my rig is 2.5 years old ( parts list at the bottom).I read a bunch of tutorials and decided it was something that I could do. I over clocked it to 4.3Ghz with an offset of 1.3V. I ran Prime 95 for 2 hours and temps never got higher than 82 degrees. I then ran IntelBurnTest, after 20 tests the temps hit 90 degrees but never exceeded it, and typically stayed between 85-88 degrees. I went back into the bios and dropped the clock to 4.1Ghz just to be safe.

I then played Guilds Wars 2 (because it’s fairly CPU intensive) for 2 hours while listening to music, all while I had real temp open on my second monitor to monitor my temps. My CPU temps never crossed 70 degrees. After I quit Guild Wars everything froze, the headphones were buzzing, mouse cursor wouldn’t move and would not respond to keyboard commands. So I held the power button till it shut down.

When I rebooted, It got to the windows loading screen, froze, BSOD and rebooted. Then it said “Preparing automatic repair,” froze, BSOD and rebooted. This time I went into Bios and reset all the setting to factory. Rebooted and it did the same thing, freeze, BSOD, reboot, attempt to repair, freeze, BSOD and reboot. I went back into Bios to fiddle with setting, and was there for 10 seconds when the Bios froze before i could make any changes. At this point it was late, so I turned it all off at the power button. Then unplugged the PSU and went to bed.

The next morning the first I did was clear the CMOS and at first boot up went into the BIOS. Everything was at factory settings and it did not freeze up, so I attempted to boot into windows but the same thing happened the night before. At this point I’m thinking corrupted sector on my SSD and throw in my restore disc to fix it. It asks to hit any button to boot from CD/DVD I do, I see the windows loading screen, the disc drive spins up and my computer freezes, BSOD and reboots.

At this point I go into full hardware check. I disconnect all RAM, USB devices (except Keyboard and Mouse), GPU, Optical Driver, SSD, and HDD from the motherboard. I checked the RAM one stick at a time in each slot; I was able to get into the BIOS each time with no freezes in bios with all sticks in all combos. I then left one 1 stick in and tested the SSD and then HDD and then both. Again each time I got into BIOS without BIOS freezing up but was never able to get into windows.

At some point near the end of this hardware check, (I think after connecting the SSD but before the HDD) I was searching the internet for more information while idling in BIOS probably no longer than 10 minutes). I was on the screen that shows Temps, and they were hovering around 30 degrees when all of a sudden the computer just shut off. I hit the power button and got no response. I hit the PSU switch in the back, unplugged it, waited 5 minutes, plugged it back in, hit the switch and the computer was responsive, I was able to get into BIOS again and mess around.

The last thing I did was try to access the SSD and HDD, so reconnect the optical drive, put an Ubuntu live CD(9.04), I was able to get to the menu where I can pick my language, then when I pick the option to try Ubuntu without making any changes to the computer, it goes to the normal “Loading_ Please wait” screen, the CD spins up, stops and the screen hangs, no blinking lights on the optical drive. I know the optical drive was fine because used it last week to watch a movie.

So here is where I think I stand (please correct me if my assumptions are incorrect)
1. The CPU, motherboard, RAM, and CPU cooler are most likely fine- I wouldn’t be able to get into BIOS otherwise and temps would not be under control. Also I wouldn’t get any info from the optical drive to the monitor if the MB was fried, right?
2. I’m leaning toward my PSU dying. I think this due to the random shut down while idling in bios, and the optical drive quitting at full spin up. If my PSU was under powering my SSD and HDD, it could cause the OS from loading, correct? I also know that it’s possible, if the PSU crapped the bed, that the other peripherals could be fried, I hoping not though.
3. I need advice on what to do next. I don’t have spare parts to replace out and check. Do you think getting a power supply tester would be a good next step? Does it seem like I’m on the right track, or am I way off?

CPU: Intel i5-3570K
Cooler: Corsiar H80i
MB: Asus P8Z77-V LK
RAM: 16gb (4x4GB) Corsair Vengeance @ 1600MHz 9-9-9-24
GPU: GTX 970 Gigabyte Windforce G1
HDD: Seagate Barracuda 1TB (All files, most programs)
SSD: OCZ 128GB Vertex 4 series (OS and a handful of games)
Optical Drive: Lite-ON ihbs11204 Blueray/dvd/cd burner/player
PSU: [strike]OCZ ModXtream Pro 700watt[/strike] EVGA Supernova G2 850

Update 6/8/2015
I got a new power supply, an EVGA Supernova G2 850W. With the new PSU in the system, the problem persists. While I was waiting for the PSU to arrive, I made a Lubuntu live USB, with persistence and was able to access the SSD and HDD from a different computer ( an 11 year old Dell that's been collecting dust) by removing the HDD in the dell and running the OS off the USB drive while checking the drives from my main computer. The USB also has memtest on it, so I ran memtest on my ram while sitting in the busted gaming PC. Memtest ran fine, no errors in the memory. (I couldn't do this in the old machine because it used DDR2 memory) I also removed the H80i and replaced it with the stock intel heat sink to make life easier, and re-seated the CPU during the process to cover my bases. I even disconnected the front IO and was using a screwdriver to turn on the computer.

So set up the new PSU. Only connected the 24pin MB, 8 pin CPU, one stick of ram. booted up and got the beep from MB speaker that it posted (one short beep). Turned it off.

Took out RAM. Powered on, and got the MB alarm for no RAM. Turned it off.

Reinstalled the RAM, then Keyboard, Mouse and Monitor . Post, then was able to get into BIOS. no freezing.

Rebooted, this time into the live usb. I was able to actually get into the OS for the first time. About a minute into messing around (opening folders) the whole thing froze on me. I shut it down.

Then, to be thorough, I reconnected the SSD with windows on it and it still froze at he windows splash screen.

I tried one last thing before giving up. I took the old HDD (Windows XP) out of the dell and installed it in the new machine. I got a BSOD after passing the bios screen with an actual error code this time. STOP: 0x0000007B (0xBACC3524, 0xc0000034, 0x00000000, 0x00000000)
now this looks like a boot drive error, but i know the HDD works. I had been screwing around with the dell without a problem all week.

So, at this point, I think I'm looking at a borked MB or CPU.
What confuses me, is that I'm able to run memtest and get proper alarm codes from the MB but it just refuses to boot into any OS.