Question Pc stopped working - but now works fine

[Alonbs]

The story ends well for me, but still I am a little concerned.

So yesterday I shut down the PC just before I went to take my dog for a walk. When I come back I've notice the PC is still on, only without monitors or any response.
I'd figured it was some sort of an update so I waited for few minutes. When nothing happened, I thought I''ll force it to shut down and then turn it on again.

When I turned it on again, it was the same as before I shut it down: All the fans were working, the RGB lights as well, but I got no display and no USB connectivity.
Ok - so I shut it down again, unplugged it, and shut down the PSU, and gave it 4 hours or so. When I returned and turned it on again - the same thing - no display, no USB etc.

I started reading online and saw that it ranges from fried MOBO to power surge etc.
So today I thought I'll try to break it down.
I took out the GPU, the mouse, the keyboard, 1 screen, and 1 ram slot.
I turned it on again - and it booted.
So I started re plugging things, one by one, each time tried to boot, until finally I plugged GPU and 2 monitors - and it booted normally.

It seems that I was lucky, but now I'm a little concerned as to what happened, and maybe next time things won't get better.
Is there anything you would recommend me doing ? should I be aware of something ?
maybe this happens from times to times?

I took the opportunity to clean the dust (though it was pretty clean), and update bios and GPU drivers.

My PC specs:
Mobo: Asus Prime Z370-A
Cpu: i7 8700 (non k)
GPu: 1080ti
Os: Windows 10 dual boot with Ubuntu 18.04

 

[Grobe]

Wild guess : check if the cmos battery is dying.

 

[Alonbs]

is it really a possibility ? I've built this pc only 6 months ago.
If it was dying - wouldn't I expect some out comes - like time loss etc. ?

Also - is there a way to verify this via software or bios ? (I've looked in Asus bios and I'm not sure where to look, if it's there).

 

[iMatty]

CMOS battery is not responsible for the PC to act as off but everything is running, what CMOS battery is responsible for keeping the configuration and such loaded when the pc asks for it nothing else.

Would you please include the model and make of your power supply?
And when did you update your bios before this happened or after?

 

[Grobe]

Ok, for a 6 month build it is not likely it's cmos battery - hence the "wild guess". However - i have experienced rare cases of strange behavior for mobo, that actually was seemingly fixed after replacing cmos battery. Also that was a case where it didn't loose clock (but running further would of course resulted in clock reset too) It was several years ago now.

But anyway, suggesting you follow up what iMatty suggests, as PSU may be the culprit.

And you can also do a RAM test, using Memtest86+ (that same tool also ship with the Ultimate Boot CD). Let it run overnight.

 

[Alonbs]

My PSU model is: RM750x by Corsair.
I updated the Bios after this happened.

I will also run the tests you suggested

 

[iMatty]

Well keep us updated when u do these test's if the issue kept occurring then your power supply might be faulty/dying.

 

[Alonbs]

Ok, so I ran the tests. I gave it 6 passes, so it took nearly 20 hours. Everything passed fine.
So, any suggestions what I can do next ?

The PSU is also rather new. Are there similar tests I can run to check its status ?
I should say that the PC was pretty clean, but the dust filters of the PSU were dusty - so maybe it has something to do with that.

 

[iMatty]

When did you buy that power supply?

 

[Grobe]

Have the computer had any issues after you updated the bios ?

 

[Alonbs]

iMatty: I bought it 6 months ago, the same time I've built my pc.
Grobe: no. There were no issues apart the one that I described at the beginning of this post (which was before update).
I'm not sure if the bios update has anything to do with that - but the problem has not occurred again - yet.