Hey everyone,

I built a new PC about a month ago and it had been running perfectly fine up until about two days ago. Since then, I’ve started getting completely random shutdowns where the system just turns off instantly, like the power was cut. There’s no blue screen, no freezing beforehand, and nothing useful in the logs other than Kernel-Power (Event ID 41) and EventLog 6008.

For reference, the build includes an RTX 5080, 32GB of CL30 RAM, a Corsair RM1000x Shift PSU, a B850 motherboard, a Montech 903 Max case, and a Samsung 9100 Pro SSD.

One thing that might be a coincidence, but worth mentioning, is that the same day this started happening we had an electrician working in other rooms of the house (just changing light fixtures). My PC is set up in the basement, so I’m not sure if that could be related.

The behavior has been pretty inconsistent and confusing. At first, the PC would try to start (fans spinning) but then shut off without actually booting. At one point, unplugging an external HDD seemed to fix it and allowed it to boot, but then later it failed to boot again even without the HDD connected. I also noticed that removing the side/back panels of the case somehow allowed it to boot, and after putting them back on it worked again, which made me think maybe something physical like a cable or pressure issue could be involved.

Right now, the system does boot, but I’m getting random shutdowns even during very light use like browsing or reading PDFs. What’s strange is that under heavy load it seems completely fine — I was able to play Cyberpunk 2077 for hours without any issues. Because of the earlier behavior, I’ve completely removed the external HDD for now, but the crashes are still happening.

At this point I’m not sure where to start since the crashes are so random and leave no useful trace in Event Viewer. It really feels like a sudden power loss rather than a typical crash.

If anyone has ideas on what this could be or what I should test first, I’d really appreciate it. I can provide more info like temperatures, voltages, BIOS settings, or anything else that might help narrow it down.