PC hangs weird. How to diagnose a problem?

Question

Iron

Several times a week the computer freezes tightly: the mouse does not move, does not respond to the keys; only reboot saves. PC 5 ​​months. The problem began to appear a month or two ago. Basically, when I watch a video (YouTube, Twitch) in chrome, although maybe not only there (I don’t remember). I sinned on the OS and drivers, but the behavior is the same on Windows 10, on Ubuntu 17.10.
I thought the video card was overheating, but I recently played GTA V at maximum speed for several days - it never hung.
I understand that no one was given a crystal ball, but maybe you can advise where I should dig or some diagnostic programs?
i5 7400 (thermal deepcool z5), ASUS PRIME B250M-K, GTX 1050TI, Silicon Power Slim S55 SSD, fan TITAN TFD-12025GT12Z, DIMM PSD48G240081 DDR4 8Gb
Update: once in Windows it did not freeze, but rebooted with a BSOD, I did not have time to read what was written there. Is this info being logged somewhere?

Answer 1

Silicon Power Slim SSD

I'm hanging tight because of him. There was a laptop with a regular HDD, it worked fine. I added RAM and swapped the HDD to such an SSD. Problems similar to yours appeared (however, from time to time the BSOD also crashed). Replaced it and everything was back to normal.

Answer 2

I would run stress tests on different devices (cpu, ram, hdd, gpu).
I would start with memory in ubuntu memtest, stress