Does this look like PSU malfunction

[StackUnderflow]

Hi,

 

I have a machine that was stable for 5 years, recently it began shutting off by itself.

 

I started with running Prime95 and after a few seconds it'll just shut off. I tried underclocking and undervolting from 4.2GHz to 3GHz and 1.3V to 1V and it ran Prime95 for longer (a minute or so) before shutting itself off. 

 

Is this indicative of PSU malfunction or is something else broken?

 

Thanks,

 

P.S. I ran HWinfo along with Prime95, thermals are fine.

[Juular]

It shuts down without turning on back ?

[Bombastinator]

Shutting down or crashing?  Orderly or *bamf*?
 

machine specs also useful. Are they the ones in your sig?

[StackUnderflow]

8 minutes ago, Juular said:

It shuts down without turning on back ?

 

It's as if someone pulled the power plug. It does turn back on by itself I think I have that on the BIOS.

 

6 minutes ago, Bombastinator said:

Shutting down or crashing?  Orderly or *bamf*?
 

machine specs also useful. Are they the ones in your sig?

 

Crashing like if someone pulled the power plug. No blue screens no errors, everything's fine then it's suddenly off.

 

I've also tried running furmark and that doesn't seem to crash it, at least not yet.

 

Machine specs:

• CPU
  Intel i7-6700K
• Motherboard
  MSI Z170I AC
• RAM
  Corsair Vengence LPX 32GB (16GB sticks)
• GPU
  EVGA GTX 980 SC
• Case
  Fractal Designs Core 500
• Storage
  Samsung 850 Evo 250GB
• PSU
  Cooler Master VS 550W

   

   

[Juular]

12 minutes ago, StackUnderflow said:

It's as if someone pulled the power plug. It does turn back on by itself I think I have that on the BIOS.

That's called hard reboot. If it's not thermals then it maybe RAM, or unstable CPU\motherboard, possibly PSU too. Check RAM with MemTest86, and find some spare to replace and test other suspects.

[StackUnderflow]

1 minute ago, Juular said:

That's called hard reboot. If it's not thermals then it maybe RAM, or unstable CPU\motherboard, possibly PSU too. Check RAM with MemTest86, and find some spare to replace and test other suspects.

This is weird but it fixed itself...

 

I did nothing and Prime95 (all the options smallest FFT to blend) runs fine for at least a minute and no shutdowns...

 

I'll run MemTest85 and if it doesn't come up with anything I'm just going to chalk this up to unclean power and hope it doesn't happen again.