Computer won’t start (or shuts off)

BMF96

Distinguished
Sep 19, 2012
128
0
18,680
I was away for a few months and it’s possible I left my computer on hibernate while I was gone. When I came back it was fine but I think it shut off randomly once in a while. One day it stopped turning on. I swapped cables and tried a different outlet. I let it go for a couple days and it turned on again, but turned back off after about a couple minutes. Then it would only stay on no more than 30 seconds. Later, I noticed it was constantly turning itself on and off, so I unplugged it.

I figured it was a safe assumption it was the power supply and I bought a tester. I built this pc around 2013 and haven’t replaced a part since then (except changed stock fan and added drives) so I’m a little rusty. I’ll upload a pic of the tester with just the 24 pin connector in.

http://imgur.com/c1ZEr31

Here are my main specs in case it helps

i5-3570K
ASRock Z77 Extreme4 ATX LGA1155
Sapphire Radeon HD 7970
XFX ProSeries 750W 80 PLUS Silver Certified ATX12V

CM Hyper 212 Evo CPU cooler
Corsair Vengeance 8 GB RAM (2 x 4gb)
OCZ Agility 4 256GB SSD
Samsung 840 Evo 120 Gb SSD
Western Digital Caviar Blue 1 TB
Seagate HDD 3 TB
Asus Blu-ray player cd writer

I’d appreciate any help you can offer.
 
Solution
you have to retry with psu so when you be able to have it turn on i would had one part at the time to see witch one made it cut and try this part in another system if it run then i would have the board check .

BMF96

Distinguished
Sep 19, 2012
128
0
18,680
Somewhat confused what you mean by open and shut it down, but it still won’t turn on. When I take out all the PCI E connectors and just leave it connected to the motherboard it still doesn’t turn on.
 

BMF96

Distinguished
Sep 19, 2012
128
0
18,680
Unplugged the HDDs and it turned on again for a matter of seconds. Then wouldn’t turn back on. Unplugged GPU and still wouldn’t turn on. Plugged GPU back in and a minute later it turned itself on and then off again.
 

BMF96

Distinguished
Sep 19, 2012
128
0
18,680
Sorry I’ve been super busy with work the last week. So I unplugged the GPU and the drives and tried each ram stick with the SSD and it doesn’t turn on. Not sure why it sometimes would turn on momentarily. Maybe it had to do with the power cable being left plugged in to the PSU and gaining a charge?
 

BMF96

Distinguished
Sep 19, 2012
128
0
18,680
So I tried another working power supply of the same wattage and at first it turned on. I believe it started turning itself off and on. Then I plugged in the GPU and ssd and it wouldn’t turn on. So I unplugged them and it would not turn on even though it did before.

I decided to try my power supply in the computer I took the other PSU out of and it turned on once before I plugged in components and then would not turn on again.

It seems like there may be something wrong with both the power supply and the motherboard.