The PC shuts itself off once in every single day randomly

[ceyhunyuzuak]

PC turns off instantly without any sign and goes to black screen as if I unplugged it for a millisecond.
it has always done the same thing since the very first day I had built it.
I purchased all the components at the same time and I have been using it as I had built in the first day. no components have been added or removed.
Right after the shut off I am able to turn it on back without waiting.
It shuts off any time, when idle, playing games, watching movies, browsing internet etc.
PC runs pretty well beside that.
Checked the temperature values, no overheat.
no OverClock on any module
memtest86+ run for a night long with 8 passes and zero errors (checked it like a couple of weeks ago)
drivers are up to date
bios up to date
I freshly reinstalled windows 2 times. nothing changed.



the setup is:

• 
  CPU: Intel Core i7 4790K 4x 4.00GHz So.1150 BOX
  Graphics Card: 4096MB Asus GeForce GTX 970 STRIX OC Edition
  HDD: st3000dm001-1er166 (I know, these are problematic HDD series from SeaGate. I learned that after I got it.)
  MOBO: Asus ROG MAXIMUS VII HERO Gaming MB Intel Z97 So.1150 Dual Channel DDR3 ATX
  PSU: Cooler Master V550

 

[jr9]

When it shuts off, is it a complete shutdown?

Do you have to press the power button to get it running again?

Do you have to load into Windows again?

If your answers are yes, yes, and yes then your power supply is possibly failing if your temps are good as you say there are.

 

[R0GG]

sounds like a PSU issue, when you power your system back does windows attempt to scan your drive for consistency ? (unproper shutdown), could you check your system event viewer for warnings and such, thanks and good luck.

 

[ceyhunyuzuak]

When it shuts off, is it a complete shutdown?

Do you have to press the power button to get it running again?

Do you have to load into Windows again?

If your answers are yes, yes, and yes then your power supply is possibly failing if your temps are good as you say there are.

true, all yes. thanks.

sounds like a PSU issue, when you power your system back does windows attempt to scan your drive for consistency ? (unproper shutdown), could you check your system event viewer for warnings and such, thanks and good luck.

no it doesn't scan anything. when you causally come home and hit the power button of your pc to run and it boots smoothly, mine happens just like that.

 

[R0GG]

Thanks for the prompt answers, one more question,
- When windows shuts down inadvertently does it shut down the regular way (windows is shutting down message ) or does the screen just black out, or display some messages?
- Does it happen with the usual hard drive saves activity (hard drive led blinking) (even with a black screen) at shutdown or it happens abruptly?

 

[jr9]

If it shuts down without any kind of warning or shutdown notice such as the shutting down screen then that generally points to an electrical problem especially if it was in use. I would first go to power options and make sure the PC is set to high performance and that it isn't set to sleep or hibernate after a certain period of time. That could be what it's doing.

Most times this is the power supply if you have random shutdowns out of nowhere. Overheating can also cause this if the CPU cooler or thermal paste wasn't installed correctly. Checking your CPU and GPU temps in a stress test program like OCCT could verify this. OCCT also has a PSU test tool that will run both the CPU and GPU and max to see if the PSU can handle maximum stress.

Far less often a failing motherboard is to blame.

 

[ceyhunyuzuak]

If it shuts down without any kind of warning or shutdown notice such as the shutting down screen then that generally points to an electrical problem especially if it was in use. I would first go to power options and make sure the PC is set to high performance and that it isn't set to sleep or hibernate after a certain period of time. That could be what it's doing.

Most times this is the power supply if you have random shutdowns out of nowhere. Overheating can also cause this if the CPU cooler or thermal paste wasn't installed correctly. Checking your CPU and GPU temps in a stress test program like OCCT could verify this. OCCT also has a PSU test tool that will run both the CPU and GPU and max to see if the PSU can handle maximum stress.

Far less often a failing motherboard is to blame.

wait wait wait wait wait...
ok I noticed something unusual that I have been missing till now. when I launched the OCCT it showed my CPU is OCed by 10%. I went to the intel web page to see the specs of my CPU and yes, it is supposed to run on 4000mhz but it runs on 4400mhz. what is weird is my BIOS settings have always been on Default settings which shows the clock speed of the CPU as 4000mhz on the UEFI screen

I have always been using" maximum performance" on the power options settings on windows, which causally has been running the CPU on 4400 mhz for years now.
I created new power option and decreased the maximum CPU usage to 99% and 90% with this order and got 3960 and 3600 mhz max CPU clock speed. Ok these are mathematically correct but when I set it to 100% it jumps up to 4400 again. When you consider I have been using the stock CPU cooler fan (yes, please judge me ) I usually get BSOD because of the temperature values when I torture the CPU.

Now I have 2 new questions.
how can I run it on 4000 mhz?
why does it OC itself?

 

[jr9]

UEFI settings and Windows are independent of each other. Windows does not overclock your CPU but sets limits on CPU usage. UEFI CAN overclock however. Undo whatever power saving tweaks you did in Windows as those are not going to help. Go into your motherboard settings and see if there is an easy system tuning utility and set it to something like power saver if you do have it set to something like high performance which is like a mild overclock.

Intel Processors can also overclock automatically if they have Turbo boost enabled.

 

[ceyhunyuzuak]

UEFI settings and Windows are independent of each other. Windows does not overclock your CPU but sets limits on CPU usage. UEFI CAN overclock however. Undo whatever power saving tweaks you did in Windows as those are not going to help. Go into your motherboard settings and see if there is an easy system tuning utility and set it to something like power saver if you do have it set to something like high performance which is like a mild overclock.

Intel Processors can also overclock automatically if they have Turbo boost enabled.

yep. turns out the mobo default settings are actually OC for the "K" models of i7s. turned it off and it turbo boosts up to 4000 mhz now. Prime95 torture test barely lifted the temp up to 80C. it used to go to 100C and then BSOD. I think for now I have to wait and see if this change actually would affect my "daily shut off" problem.
thanks for your lightning fast and valuable answers.

 

[ceyhunyuzuak]

Thanks for the prompt answers, one more question,
- When windows shuts down inadvertently does it shut down the regular way (windows is shutting down message ) or does the screen just black out, or display some messages?
- Does it happen with the usual hard drive saves activity (hard drive led blinking) (even with a black screen) at shutdown or it happens abruptly?

it happens all of a sudden. it happens as if I am a schizophrenic who has never turned the PC on, sitting on chair looking at the black screen until the schizophrenia effect wears out and I realize I have been looking at nothing for hours, then finally turn the PC on.

 

[jr9]

It may have been the issue. At 100C a CPU can cause BSOD or the CPU can thermal shutdown to protect itself. This is common in the 100C area. Wait and see a few days.

 

[R0GG]

Definitely sounding like CPU overclock and/or overheating gone unnoticed, but usually you get cues from CPU fans ramping up speed .
My personal experience as I game once in awhile at times I forget to change case and CPU fan curves to more abrupt ones, or video card fan curve and I end up with sudden shut downs in the middle of gaming, later discovered that main issue was my motherboard northbridge overheating ( Asus CrossHair Formula V NB temp above 74C ! contaminating other components) because of the lack of airflow ( due to CPU water cooled with AIO) so even though temps of CPU and GPU were high but were still within specs, when I ramp up case Fan curves I do not get any overheating issues, so make sure you have a good case air flow and adjust fan curves accordingly. Also is a good practice - especially when getting acquainted with new hardware or PC- to to verify your components clocks and Fan curves and temps upon boot: it helps to have few monitoring software visible at all times on a second monitor or use of in-game hardware monitoring overlay software like Riva tuner and HWinfo etc. As mentioned above windows CPU/RAM overclocking software - if set to load automatically at windows startup- will override Bios parameters (CPU RAM and FANS) once system is loaded.
Newer intel CPUs and mobos Bios have advanced automatic boost/overclock features that could cause very sneaky overheating as well as power saving options as mentioned above that have to be accounted for and taken care of diligently at the bios level.
Also some overclock on the CPU or the Ram may become suddenly unstable at times even with light system load or with higher system load and cause sudden shutdown.
I would run this system at stock speeds (double checked at start up) and use few monitoring softwares (HWinfo, speedfan,etc), stability test is key when overclocking too.

 

[R0GG]

Thanks for the prompt answers, one more question,
- When windows shuts down inadvertently does it shut down the regular way (windows is shutting down message ) or does the screen just black out, or display some messages?
- Does it happen with the usual hard drive saves activity (hard drive led blinking) (even with a black screen) at shutdown or it happens abruptly?

it happens all of a sudden. it happens as if I am a schizophrenic who has never turned the PC on, sitting on chair looking at the black screen until the schizophrenia effect wears out and I realize I have been looking at nothing for hours, then finally turn the PC on.

Man ! What a deep and funny description for the pseudo-paralysis state in front of the PC screen !

 

[diellur]

If the CPU OC issue sorts it, brilliant.

I did have a similar/identical issue recently with my system. It would randomly turn off and on again, irrespective of what I was doing (gaming, desktop tasks, watching a movie, browsing etc). It was like I had hit the case reset button. Every once in a while it wouldn't come back on for a minute or two, even if I hit the power button. I RMA'd the PSU, got a replacement, and the problem has gone. So yeah, next option would be to swap out the PSU if the problem recurs.