New build. 3950x, MSI Meg Unify x570, 64 GB RAM,
System worked without issue for about 2 days, using both Windows10 and Linux.
I was using system in Linux (but not in process of changing anything) when I got a fatal error and had to reboot the machine. Have not been able to successfully boot into OS since. Can get to BIOS fine. During boot process, it immediately reboots at start of boot. Won't boot for any disk or USB.
The only way I've been able to get in was via Linux turning ACPI off in GRUB, but then I only get 1 core.
Normally it is impossible to see any error messages during boot as it happens so fast, but I was able to capture this one of the times.