System suddenly shut off and won't start

[Danny OShaughnessy]

Hey guys,
This morning I was browsing the web on my PC when it suddenly shut off for no reason, all lights, fans, everything shut off. I unplugged the power cable temporarily and put it back in, the lights and fans came on for about half a second then went off again, and this happened a few subsequent times (but not every time)
Any ideas as to what has happened and what I can do to fix the system? The system was built over a year ago and this is the first time I have had a major issue.

Specs below:
CPU: Intel Core i7 4770k
CPU Cooler: Cooler Master Hyper 212 Evo
Motherboard: MSI Z87-G45
RAM: Corsair Vengeance LP 16GB (2 x 8GB) DDR3-1600
Storage: Samsung 840 Evo 120GB
Seagate Barracuda 1TB 7200RPM
GPU: MSI Twin Frozr 780Ti
PSU: EVGA G2 750W
Wireless Adapter: ASUS PCE-AC68
Sound Card: Creative Sound Blaster Z
OS: Windows 8.1

 

[smorizio]

can be one of two issues...a dead short in a part...causing the power supply or mb not to turn on or the power supply failed. for the first issue if the mb has onboard video...take the video and sound card out and disconnect power to the drives. see if anything changes,if not time to try a known good power supply.

 

[bgunner]

Sounds like the power supply's protection circuitry is kicking in cutting power to prevent damage.

Check for shorts in the case, wires burnt, connectors plugged in all the way. After this you may want to try a known good PSU to be sure the PSU is OK and then go from there. A component some how has an issue either shorting out or just totally died.

 

[Danny OShaughnessy]

Hey guys, I just went to check it out, and tested the cables were all connected and decided to power it on just to be sure before removing any components; and guess what, it worked first time! I turned it off and on a few more times and it was fine. So I took it back to where I have it set up, reconnected everything and it was still working; I temporarily left the room and as I returned it had just restarted, which I thought was odd, so ran the passmark benchmark to make sure all was in order, everything seemed fine until about halfway through the system cut out again and now won't start, just as before; as a guess I'd say that this is an issue with the PSU but I don't know; does this help pinpoint the issue?

 

[Danny OShaughnessy]

Another update, started it today and it was working, thought I'd remove the minor overclocks I had on the CPU and GPU; and suddenly it seems fine, completed the Passmark benchmark with no issue; could this be that one of the overclocks became unstable? I just want to understand the issue and hope it doesn't happen again

 

[bgunner]

It is quite possible that your OC was causing the issue. This is not to say that I am positive this is the case though. I recommend doing a complete stress test suite before saying the problem is gone.

CPU stress test to perform: Intel Burn test : set to maximum stress and 20 runs. Also run (at a separate time) Prime 95 for a minimum of 2 hours 8 hours preferred.
GPU stress test : OCCT : on GPU test set shaders to 3, enable error detection, run for minimum 1 hour *do not use PC during stress tests. Let it work on its own.
Memory test : Memtest 86+ : run from disk or flash drive and run as boot device. Run for 2 passes minimum.
HDD/SSD : HDDscan3.3 : can read smart sensors and run HDD stress tests if necessary.

this should stress the separate parts individually to make sure each part is stable. Just running passmark will not do the trick to say the whole system is stable.

Any time you have an issue with an OCed system always start by removing all the OC's and see if that is the cause to eliminate it as a reason. Just for future reference.