Windows 10: Random system crashes

Computer randomly shutting down without a bluescreen. Has occurred during gaming as well as general productivity apps. I've included system and application logs (onedrive links below) for reference. Shutdowns occurred at the following dates/times:
4/26/19: 11:47am
4/25/19: 10:26am
4/24/19: 9:42am

https://1drv.ms/f/s!Ao5nEHSTO4NGaTaYnN_W5A26Stk
https://1drv.ms/u/s!Ao5nEHSTO4NGggN3cSUmAjGZ9p8W

:)

 

all games crash!

I suggest you run rthdribl > http://www.daionet.gr.jp/~masa/archives/rthdribl_1_2.zip
Increase the window size step by step and watch your vga temps permanently.
What happens?
If it crashes, run at stock speeds as suggested before and retry.

P.S.: When your system locks, does the display signal turn off after a time?
Stuttering sound or no sound at all when freezing?
What X1800XT model do you own exactly?

 

Random system crashes

Hmm, that's odd.

Can you select that device, right click -> properties -> driver -> driver details and send me a screenshot of what you see there, if that iusb3* driver appears in the list?

Please also let me know if you've hit that crash again since following the steps above.

 

Random BSOD while browsing internet


BitDefender is nothing special. mwac.sys causes BSODs anywhere.
A tiny documentation can be found here: Solved Random BSODs - Windows 10 Forums
In that very thread, the suggested action apparently worked.

The storage and network filters of any third party antivirus can cause BSODs. Neither MBAM nor BitDefender is any special. For a regular antivirus, it may be shifted to an alternative; but MBAM has no alternative. So a clean install of the said program is the most feasible first step.
As far as the first step is not failing, it is better to not think for the second step. Because the BSODs are not universal, failure at the first step is not universal; and success at the second step is also not universal.
That is why I posted that my suggestion may work, or may not. Let us see where it goes.