Question Any idea why computer could start rebooting randomly?

SaltyUser199

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Jun 8, 2019
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I have a computer that is several years old. Desktop. A Power something or other, got it from MicroCenter on the cheap. Very decent components at the time (I remember it had a 1060 graphics card).

Lately, its been rebooting randomly. It seemed to happen more often when I was playing games or using it heavily, so I figured maybe the case fan or CPU fan went out and it was getting to hot. But I opened it up just now and both are running fine.

I had a problem where the "power on" button was sometimes getting stuck, and I have to play with it to get it to come back out before it turns right back off after I press it to come on, but that was awhile back and now it seems to be popping back normally. So I don't think its tied to that.

Any ideas what might be causing it to spontaneously reboot?

Thanks!!!
 

Aeacus

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3 reasons:
  1. Too high CPU/GPU temps.
  2. Poor PSU and/or PSU is on it's way out.
  3. Main electrical grid issues (blackout/brownout etc).
1st option is easy to validate, just download HWinfo64, run it, keep it open when gaming and look what your temps are doing.
Link: https://www.hwinfo.com/download/

2nd option is most scary, since when PSU does go "pop", depending on what you have, it can fry everything it is connected to. Aka your whole PC.
So, PSU make and model (or part number) is? Also, how old the PSU is, and was the PSU bought new or used/refurbished?

3rd option also costs money. And is quite scary, since for the very least, it can lead to data corruption. For the very worst, it can kill your PSU, which in turn, can kill your whole PC.
Fix is easy, by buying good quality UPS (CyberPower, TrippLite or APC). Preferably line-interactive, true/pure sine wave. So when electrical grid throws it's tantrums, your PC stays running.

Oh, what's the full specs of PC as well, besides PSU (which i asked for) and GTX 1060 (you shared)?
 

SaltyUser199

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Jun 8, 2019
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Thank you so much Aeacus! On #1, going to go start up computer and try and dowload that and run it now! Will report back.

On second one, let me try and get that info off it - it came with the computer when I bought it from MicroCenter.

Not the 3rd one - only the computer is resetting - everything else in the house electricity wise is running fine with no issues.

Will report back in a bit. Thanks!!!
 

Aeacus

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On second one, let me try and get that info off it - it came with the computer when I bought it from MicroCenter.

Easiest way is to take a picture of PSU's label and upload it to net, e.g www.imgur.com whereby afterwards sharing the image link here.

Not the 3rd one - only the computer is resetting - everything else in the house electricity wise is running fine with no issues.

Still, there is a possibility, since PCs are extremely sensitive to power loss, even those that you have 0 idea happening of.

How come? Well;
All PSUs, according to ATX PSU standard, must have hold-up time of at least 16ms (milliseconds). Meaning that when power is lost for up to 16ms, your PSU can keep your PC running.

Do you have any idea how short of a time 16ms is? :unsure: 1 second is 1000 milliseconds. Average human reaction time is 150-300 milliseconds. So, when there was a power cut, between 16 and 150 ms, you even didn't notice it, while it was more than enough for your PSU, to shut down your PC.
So, just because lights didn't flicker and/or you didn't noticed it, doesn't mean there wasn't a power loss.

Line-interactive UPS has transfer time of 2ms, from the moment of power loss to the battery power. Which is more than enough time for PSU to keep the PC running during transfer time, but completely un-noticeable to every human.

I have UPSes in use with my PCs and sometimes, for a split second, i've heard my UPS to switch to battery power and then back to main power. Just because i didn't notice a power cut, that was only some milliseconds long, doesn't mean there wasn't a power cut. There was, and my UPS also catched it, keeping my PC running without issues. :)

In my opinion, every PC should be backed up by an UPS.
 

SaltyUser199

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Jun 8, 2019
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Thanks Aeacus!

Power supply picture:



6ozEL4R.jpg






I thought I had found the issue - the GPU fan did not appear to be working. But I downloaded the program you linked, and played World of Warcraft just a bit, Both CPU and GPU temps got into mid/high 70s I think, Celsius. Is that normal? I also saw (in the program) and felt (with my hand) the GPU fans kicking on a little.

I think it has to have something to do with temps as it went for a good while after I started it after letting it sit for awhile before it restarted, but then as soon as it did, each time it automatically tried to power back up it restarted every time in short order, before it could even boot up. Like it took awhile to get hot and reboot, but once it did reboots were quick.

Thanks again!!!
 

Aeacus

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Both CPU and GPU temps got into mid/high 70s I think, Celsius. Is that normal?

Without knowing what CPU you have, hard to say. But most CPUs are fine up to 80C. 80-90C means CPU thermal throttle and performance reduction when 100C = PC shutting itself down, to avoid CPU burning up.

Now, these threshold values can be lower, depending on what CPU you have.
To know the chip you're running, you can either look the name from HWinfo64, or download CPU-Z,
link: https://www.cpuid.com/softwares/cpu-z.html

GPU wise, same thermal thresholds apply.

Power supply picture:

You have EVGA W1 500W. Sadly, that is a low quality PSU and most likely the root cause of all your issues.

For 2nd opinion how bad your PSU is, it is Tier D, low priority unit. Essentially borderline Tier E unit,
PSU tier list: https://forums.tomshardware.com/thr...er-list-rev-14-8-final-update-jul-21.3624094/

While proper PSU for gaming PC, would be anything from Tier A. Like Seasonic Focus/PRIME or Corsair RM/RMx/RMi. Wattage range of 550W will do. 650W is also good.

(All 3 of my PCs are also powered by Seasonic. Full specs with pics in my sig.)

-----

Also, i see that the innards of your PC are so very dusty. When was the last time, if ever, you cleaned your PC from inside? Since when dust collects, it worsens thermal performance a lot. Dust is great heatsink, trapping heat into it, without letting it dissipate.
 

SaltyUser199

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Jun 8, 2019
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Thank you Aecus!

The more I think about it, the more I think you are right about the power supply. I thought it must be a heat issue - i.e. when I start playing a game that causes heat to rise in case and that causes CPU/GPU to get too hot and hiccup (and reboot). But that could also be from the GPU starting to pull more power and the power supply not being able to keep up, correct?

At the back of my mind I seem to remember I had PC rebooting randomly many, many years before (decades maybe!), and it was indeed the power supply.

How hard is it to replace the power supply? Should it be as simple as unscrewing it, taking off a few power connectors, screwing the new one in and attaching the (new) power connectors? I have not built or been inside a PC for many, many years. :)

CPU is an I5-6600K.

I ordered some compressed air to try and get rid of some of that internal dust.

Thanks!!!
 
Thanks Aeacus!

Power supply picture:



6ozEL4R.jpg






I thought I had found the issue - the GPU fan did not appear to be working. But I downloaded the program you linked, and played World of Warcraft just a bit, Both CPU and GPU temps got into mid/high 70s I think, Celsius. Is that normal? I also saw (in the program) and felt (with my hand) the GPU fans kicking on a little.

I think it has to have something to do with temps as it went for a good while after I started it after letting it sit for awhile before it restarted, but then as soon as it did, each time it automatically tried to power back up it restarted every time in short order, before it could even boot up. Like it took awhile to get hot and reboot, but once it did reboots were quick.

Thanks again!!!
I can only imagine the dust INSIDE that PSU! Time for a cleaning.
 

Aeacus

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The more I think about it, the more I think you are right about the power supply. I thought it must be a heat issue - i.e. when I start playing a game that causes heat to rise in case and that causes CPU/GPU to get too hot and hiccup (and reboot). But that could also be from the GPU starting to pull more power and the power supply not being able to keep up, correct?

Both are correct.

When your GPU heats up, it tries to cool itself by fans. If fans/heatsink is filled with dust, GPU temps may keep rising, until the point of automatic shut down. Same is with CPU. Hence why clean PC from dust.

Same is with PSU as well. It too has fan in it, which can draw in loads of dust, hindering it's operations. And since your PSU is poor to begin with, it doesn't take much for it to act up.

How hard is it to replace the power supply? Should it be as simple as unscrewing it, taking off a few power connectors, screwing the new one in and attaching the (new) power connectors? I have not built or been inside a PC for many, many years. :)

Quite easy actually.

Your EVGA W1 is fully-wired PSU, meaning that you can not remove the PSU before you disconnect all power cables. Which are: 24-pin ATX, 4/8-pin EPS, 6/8-pin PCI-E (to your GPU) and SATA/MOLEX cables to your drives and fans.

Most proper PSUs nowadays, are fully-modular. Meaning that you connect only those power cables that you need. Main diff to the fully-wired PSU is, that fully-wired PSU has to fit all it's cables, including unused ones, into your PC. Severly restricting airflow.
Here's further reading about PSU modularity: https://www.cgdirector.com/full-vs-semi-vs-non-modular-power-supply/

So, once you get your new PSU, it also comes with guide, to tell what cables are what. Also, you can't connect power cables wrong, since e.g while 4/8-pin EPS and 6/8-pin PCI-E look similar, they are keyed differently and can't be plugged into the wrong slot.
Further reading of PSU connectors, to get you up to speed: http://www.playtool.com/pages/psuconnectors/connectors.html

Here's a video about changing PSU, starts at 02:04;

View: https://www.youtube.com/watch?v=bW3SWQPY19M


The tasks done + PSU fan orientation is well shown/talked about. Other info about PSUs in that video, is either poor advice (e.g using EVGA B5 PSU, which itself, at best, is mediocre quality unit), very bad advice (e.g buying used PSU) or completely wrong (e.g PSUs never catches fire and burns your PC/home down).
So, look this video for the actual tasks needed to be done.

CPU is an I5-6600K.

You got the same chip as i have in my main PC, Skylake. :D A good CPU, that can idle at ~26C, while on load, mine never goes above 55C. Then again, i haven't neglected my PC, instead, i take good care of it.

Here's mine;

vgc9bNK.jpg


Fancy, isn't it? :sol:

I ordered some compressed air to try and get rid of some of that internal dust.

When you blow out case fans, use your finger to stop fan blades spinning. Since when you make the fan rotate the wrong way fast, it can kill the fan.

Btw, getting an air compressor, in the long run, is both cheaper and more practical, than just buying canned air. Less waste too.
 

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