Troubleshooting Random Computer Restarts

[Galland1998]

I am having an issue with a new-ish built (4 months ago) PC that has started having random restarts. Prior to about a week ago the PC operated flawlessly. I never get a BSOD just a reset that does not seem to be associated with high demand apps like games. It happens just as often in games as when I am just web browsing and watching YouTube. However I also have noticed that sometimes that when I am going to have a problem the PC starts to lag. Sometimes the lag is moderate and sometimes the lag is significant. When no gaming operations I will notice lag when typing or YouTube videos stuttering. In games I notice moderate to severe frame rate lag.

Since it just goes to reset, there is no error code or message. Is there a way to trouble shoot the source or do I need to start replacing random hardware on the PC.

 

As a side note the time between resets can be minutes or hours.  Also if the issue presents as lag than a system shutdown and restart usually solves the problem but not always.

 

I don't think it is a software thing since I did a fresh install of just windows and the up to date drivers and the problem still happened.

 

The PC is not overclocked and get the same problems in performance mode or normal mode on my ASRock mITX z390 board.

 

As far as specs go I have a

EVGA 2070 Super

EVGA SFX650w Gold PSU

ASROCK mITX Z390 Phantom Gaming motherboard

Intel 9700k chip

[Viper9]

It could be a overheating issue, you could run a stress test like prime95 or furmark (or both to test the CPU and the GPU) and use a utility like HWMonitor to check the temperatures. 

[Galland1998]

Well, I know you can run Prime95 for longer than I did but after 3 hours no reboots or shut downs happened.  The ASRock hard ware monitor did have temps spiking up to about 105 which seems less than ideal.  But no resets happened during those 3 hours.

[Viper9]

This is what I would try:

 

-If you can, try to use another PSU just to be sure it's not a power issue.

-You could remove your graphics card and run with the integrated GPU.

-Run a memory test like memtest86 just to be sure your RAM is alright (I know usually shutdown doesn't mean bad RAM but you never know). 

[Galland1998]

Thanks! I'll give that a try.