Lately my PC has started crashing while it plays videos. It freezes completely, screen frozen and not responding to any input (keyboard, mouse), I mean I cannot change TTY (alt + ctrl + F(1-2-...)), and it cannot even respond to alt + PrntScr + REISUB. I have to force power off by holding down the power button.

After I reboot I have tried checking all logs available and I cannot find anything logged right before the incident. Last entries are always different and not indicating anything.

I suspect it has to do with the graphics card but I'm looking for ways that I can dig deeper on that and confirm it or not.

What else should I check? How can I find more info?

OS: Lubuntu 22.04.3 LTS (latest updates) I'm using the nvidia proprietary drivers (nvidia-driver-390)

UPDATE:

First of all thank you all for your input and fresh ideas. Now I've already tried some of them and I will continue with the other ones until I get some results.

till now I have tried

• memtest and it didn't show any errors.
• boot from a live distro and see if problem also occurs. Well it didn't occur but on the live distro you cannot change the graphics driver. So it was using the open source nouveau driver, also it didn't happen during the 1 hour I let it play. The thing is that it never was punctual even before. It could happen during the first hour or the third or sometime later.

Next steps are to

• open the case and clean it up to remove the possibility of high temp because of that,
• change my drivers to be the nouveau and try again,
• try with only the onboard GPU on,
• remove extra disks to reduce the load of the PSU

thank you all again.