Any suggestions what to test next?
Built the PC 4.5 years ago, it has 4x 8GB = 32GB DDR4 3600 (poor by today's standard, I know). No problems until about a week ago and got BSOD, then again a couple of days later, then again earlier. Memtest has 0 errors after 4 hours of testing.
Always sleep, never shut down but had no problem prior to a week ago.