Random power cut outs

[Nogib]

Having trouble wrapping my head around this PSU cutout issue I'm suddenly having.

 

PC is nothing fancy (i7 4790k, 16GB ram, GTX 1060, 512GB ssd, 2TB hdd, bluray)

 

Starting two days ago I am encountering a scenario where while idle, PSU will (between 5 minutes an up to about an hour) just shut off and then turn back on.  No blue screens and nothing noted in event viewer other than "The previous system shutdown was unexpected".  And I don't use any sleep modes other than blanking the monitor.

 

But here's the kicker, while I am using it, it works just fine(!).  I can play games, beat on it with Cinebench, etc.  Just while idle with no interaction from me it will randomly cut out completely and immediately power back on.  Thought it was just the PSU itself going bad since it is now ten years old (Antec EarthWatts 650)

 

What I have tried:
Removed UPS in case that was sending a false signal, no change.
Reinstalled Windows from scratch, no change.
And just now, swapped out PSU with a spare Antec NeoECO 620W laying around, no change.

 

So right now I just leave it with a video file continually running and it will behave.  But this isn't really a solution and I am just at a loss as to what is going on here and hoping that someone might have a bright idea.

 

[Mindovermaster Global Moderator]

Well, being you tried another PSU with no improvements, I would look at your RAM, HDD/SSD, or CPU/motherboard.

 

How did you come up with the assumption that the PSU was bad?

 

Try running memtest, check if memory is OK. Also try using the HDD/SSD SMART data, let us know if you see anything wrong. Might want to reset everything, too. RAM/CPU/ 24-pin, 8-pin, etc.

 

Check your computer stability with a Ubuntu Live-CD. If it does not do thiis, then we can blame Windows now.

[Brandon H Supervisor]

I'd also try installing fresh on another partition/drive and let it sit idle for a bit to rule out corruption on your current install

[spaceelf]

I'd say either overheating issues (you might need to redo the thermal crap on the CPU, or a fan might be failing) or the capacitors on the motherboard going bad.

[Nogib]

3 hours ago, Mindovermaster said:

Try running memtest, check if memory is OK. Also try using the HDD/SSD SMART data, let us know if you see anything wrong. Might want to reset everything, too. RAM/CPU/ 24-pin, 8-pin, etc.

 

Check your computer stability with a Ubuntu Live-CD. If it does not do thiis, then we can blame Windows now.

Figured I'd give Memtest64 a shot because I was too lazy to make a Memtest86 usb.  Set it to continuously test.  I noticed after a half hour that it wasn't running anymore. Shows up as an app crash in Event Viewer.

 

So going to go for the reseat of entire system and see if that does anything.

3 hours ago, LostCat said:

I'd say either overheating issues (you might need to redo the thermal crap on the CPU, or a fan might be failing) or the capacitors on the motherboard going bad.

Not likely temp since it happens at idle (~30C).  Could be a cap issue, will have to inspect those.