Random PC instability, overvolting 3.3 rail?

TheBlank · April 17, 2021

I've been running into some weird instability in the past few months. Random explorer crashes, "memory cannot be written" errors, network drop outs, and flashing monitors especially at the lock screen, or waking up from having been locked. I replaced my RAM for a better configuration, and completely re-installed Windows 10, but the problems are getting worse, now with random power cuts and reboots. I had to repair the Windows installation every step of the updating process, (including replacing all Visual Studio elements).

Troubleshooting and stress-testing hasn't revealed anything out of the ordinary, until today when I noticed HWiNFO reporting that my 3.3v rail is randomly spiking to 4.9v and sometimes as high as 5.1v. I disabled iCUE as I know it and HWiNFO don't play well together, and still got the same result.

Could this be a sign that my PSU is the overall culprit, or just an issue with HWiNFO64 miss-reading my sensors? In that case, where else should I look?