Question PC turns off and on randomly without warning.

[Ryuka]

i bought this PC in 2014 built by the seller, i added the HDDs and the GPU.

PSU-OCZ-CXS500W
MOBO-MSI z77a-g45
CPU-i5 3450
RAM-8 GBs
GPU-GALAX GeForce GTX 1060 OC 6GB (the old 2014-2018 GPU was EVGA GTX 660 ti 3GB sc+)
2 HDDs-WD 2TB + Seastone 1TB

sry if my English is bad
this issue actually started in 2017 my PC just randomly turning off and on by itself, some times after hours sometimes dozen minutes and sometimes while starting windows.
i called the one who built my PC and he told me to bring it back to see what wrong, he told me it sounds like a PSU problem, he kept it for a week and told me he tried another PSU but the PC still keep turning off.
then he found out that my CPU cooler had a broken pin and told me thats definitely the problem so he switched the stock fan with a new bigger fan and said that the problem is fixed and my PSU is fine.
i go and get my PC back, it worked for probably 7 hours then it turned off again by itself. After hours of me trying to find the problem, i somehow fixed it by changing the power cable and plugging it directly to a wall outlet and disabling CPU turbo mode, but not sure which one of these fixed the issue.

from 2017 to 2020 worked fine and now the problem is back. but now with extra noise coming out of the PSU when off, a high pitched noise and buzz i hear when i get too close from the back of the PSU where the power switch.
Im not sure if its coil whine, i hear it when the PC is off. Its exactly the same problem from 2017, again i tried a lot of things but this time i removed 1 RAM stick and the GPU and it worked for 3 hours then i installed the GPU back and it still was fine, i kept using the PC for the last 5 days with no issues, only 1 RAM stick was removed and i was confident the issue was from the RAM...
unfortunately the problem is back today after 5 days and i lost hope this time, i really hope its a PSU thing and not my Motherboard or CPU.

Right now i only have $ 50 idk if i should get a new PSU im scared if after buying a new one ill still have the same issue.

 

[Darkbreeze]

Even if the PSU isn't to blame for ALL of the problems you are having, you should replace it. It is six years old and it was only a rather mediocre FSP built unit to begin with. It might even be older than that as most reviews of that unit are from somewhere around 2009.

I'd replace the PSU, FIRST, and then go from there if you still have issues, which you might, but it is pointless to try and pinpoint a problem with what is almost certainly an old and tired power supply that not only is unlikely to be able to do the job anymore but may have been having issues from the start.

Discussion - PSU recommendations and power supply discussion thread - Tom's hardware

Below you will find MY standard list of recommended power supplies and beyond that this thread is intended as a landing place for questions or discussions regarding specific units, platforms or related PSU tech, all of which are all welcome to be discussed here. If it's related to power supplies...

forums.tomshardware.com

 

[Ryuka]

thank you, ill just buy a new PSU this week and hope that fixes the problem.
Where i live i only found Cooler Master MWE Gold 550 and Corsair VS550 80 plus i could afford
i know i should avoid these but are they at least the same quality or any better from OCZ-CXS500W ? just for 1 year or 2 then maybe ill get a good one

 

[Darkbreeze]

That depends on EXACTLY which version of those units we are talking about. The Cooler master is probably a very mediocre unit that ALSO uses cheap secondary caps and might work ok for a while but won't last very long. Overall, I'd avoid these.

The VS depends greatly on WHICH version it is. Neither version is great, but the black and gray label version is significantly better than the orange lettering version. Honestly, avoiding both of them would be a good idea.

What country are you in and where can you purchase from or do you have to purchase from local shops? There might be something better available to you.

 

[Ryuka]

Im from Tunisia and i buy from local shops, the VS is indeed black and grey and a bit more expensive than the Cooler master one.
ill see what else i can find next time.

 

[Darkbreeze]

The black and gray label VS is ok as a placeholder but if you can do something better now, it would be a shame to waste money on a unit that you were going to replace, again, in a year. Spend the money ONE time, and get something decent. I've listed the better models on the link I posted earlier.

 

[Ryuka]

Update:
So i bought a new PSU: Corsair CX550 (2017) and a new case: CoolerMaster MB511
worked perfectly for 2 weeks and today it shut down again by itself.
I dont know what to do, please help.

 

[Ryuka]

it happened while playing a game called Hollow Knight

 

[Sohom]

Did u check the temps? What are temps? Also did u try a different socket...

 

[Ryuka]

another shutdown now, its gonna continue shutting down now every 10 minutes or so.
The temps are fine
CPU=45c
GPU=30c
in game CPU= 60c and GPU= 50c

 

[Darkbreeze]

Well, that's definitely a decent enough power supply that you shouldn't be having those issues. Chances are pretty good that this is a motherboard issue given the age of your system.

 

[Ryuka]

is there anything else i can try maybe? i cannot buy a new motherboard anytime soon, what else could make this problem? i almost tried everything expect motherboard and cpu

 

[Darkbreeze]

CPUs rarely fail unless they've been damaged because of some other hardware component failing and causing electrical damage to the CPU by shorting it through the motherboard, or unless they've been otherwise excessively overclocked, configured poorly, cooled poorly for a period of time, something that could have been avoided. They usually don't just "die" or "have problems" unless something else causes it. It can happen, but it's pretty rare to see a CPU die due to a defect.

Motherboards on the other hand are VERY common points of failure because everything else runs THROUGH the motherboard, and it is prone to fatigue and failure of onboard components like electrical traces, solder points, capacitors, etc.

If I had to make a guess between the motherboard and CPU, in a situation where a system was running fine for a long period of time and then just suddenly started acting up out of the blue with no hardware changes or "events" occurring, then I'd guess at the motherboard every time because it is the MOST probable fail point between the two. In some cases, it might be both.

Regardless, the cost of replacing an Ivy bridge era motherboard with an replacement of halfway decent value, at anything like a realistic price, is practically zero. The cost of getting a good condition Z77 motherboard, and potentially also another CPU if it turns out that is also faulty, is well beyond the value of the platform. It is money MUCH better spent towards a newer platform. You can get into a very good Ryzen system with a new board, CPU, memory for around 350-400 bucks. Maybe less in some cases.

But the bottom line is if you've tried everything else and the power supply didn't correct the issue, then the probability goes WAY up that it's the motherboard and if it is then there's not much you can do about it that doesn't involve spending money.