Random reboots with no BSODs

[csthrway]

For the last few days my PC has been rebooting at random times without BSODs. The PC will just shut down without warning and then boot up again after 1 or 2 seconds. Sometimes I will be browsing Chrome, sometimes the I'm idle on desktop but the PC will spontaneously reboot.

I searched a bit and most forums said it's either a problem with the RAM or PSU. I ran memtest86 for 4 passes (only had enough time for 4) and got 0 errors.

Things I think I've ruled out:
- CPU / GPU overheating since my max temp under load is 75C for the CPU and it's mostly crashing at idle or light load
- Windows 10 automatic updates / reboot - my internet connection is set as metered so updates don't automatically download
- RAM - ran memtest86 with no errors
- Drivers / software errors - I haven't updated or installed any new drivers or software recently

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- Original and current OS: Windows 10 Education 64-bit (have never installed another OS)
- OEM or Retail? I'm not sure which it counts as, I got it for free from Microsoft through my college.
- Age of system? About 2 months (except for SSD and HDD which are about 1 year old)

- CPU: Intel i5-6500
- GPU: EVGA GTX 1060 SC
- Mobo: MSI H170I PRO AC
- PSU: EVGA SuperNOVA 550W G2
- Desktop

Any help is greatly appreciated. Thank you!

 

[xilolee]

Hi csthrway. :welcome:

my max temp under load is 75C for the CPU and it's mostly crashing at idle or light load

Good for you! I am scared when mine exceeds 50 Celsius...

I'd try to remove the dust from fans and air slits and to disconnect/connect all devices (to ensure the correct connection devices/motherboard).
I'd also put a new layer of thermal compound on your cpu.
Did you think at a power loss in your apartment/house? Have you checked what devices are powered when that happens?
You could also try to enable spread spectrum (if it is present) in your BIOS.
Before you update the bios (yes, there were bios updates for your motherboard), enter in bios settings and wait there few hours to see if the problem appears also in that way.
I'm not sure if you can recover your machine after a power loss during the bios update, but I think you can't.
Finally (and only after you checked previous things...) you can try to update the bios (reading carefully your motherboard manual, and although you can update it from windows, I wouldn't trust it).