Help! Random pc reboots!

[Willehh]

About a week ago I upgraded my CPU from an i5 8400 to an i9 9900k. I had to update my systems bios to get it to work. Afterwards, randomly my pc would shut down and immediately start to boot back up quickly with no error messages. My bios are set to default, no overclocking. 

 

I figured my PSU needed to be upped next, I upgraded from a 500w thermaltake to an 850w msi PSU. After this the problem did still proceed, unable to replicate. Sometimes within 5 mins, sometimes hours. Has happened a couple times in the middle of a league of legends game. 

 

I checked and made sure temps are all good, cleaned out my GPU super well, thermal paste on cpu, everything is running under temp. I then checked and made sure everything was plugged in super well, reseated ram etc. 

 

I recently updated a driver and it made the two USB 3.1 slots on my mobo stop working, possibly related and shorting the board? 

 

I did driver cleans and checks, seemingly no issues with either. 

 

Pretty much tried everything I can think of at this point as well as researched as much as I could. My event logs were showing a critical error but just stating the pc had an unexpected shutdown. 

 

Current specs 

Nvidia gtx 1070 

I9 9900k 

850w msi PSU 

Asus tuf z370 mobo

256 ssd 500 external Seagate 

24 Gb DDR 4 corsair vengeance ram 

 

Edit 1: Started PC this morning, finished posting and then shut down and rebooted. No abnormal event in windows event viewer.

Edit 2: Event log showing up Critical, kernal 41 error. Attempted the trouble shooting for that, changing all power settings as well as checked for duplicate audio drivers. Changed and so far no error yet.

[Mark Kaine]

Sounds like BIOS instability to me  I had that for 2 years until a random update fixed it .

[Willehh]

5 hours ago, Mark Kaine said:

Sounds like BIOS instability to me  I had that for 2 years until a random update fixed it .

Should I go back to a previous bios update?