I have to bump this thread, because I upgraded the PSU to a Seasonic G12 GC 650W, which has higher power than the previous one, and is good quality according to https://cultists.network/140/psu-tier-list/ , but the symptoms persist.
The only suspect thing is an oops that occurs every time Linux...
I have a PC, self-built from components, that hard-freezes, seemingly randomly. Sometimes it reboots spontaneously, sometimes it doesn't. Sometimes the mouse pointer works for a few seconds while the rest is unresponsive, then everything freezes. Some other times everything freezes right away.
I...