Question laptop freezes sometimes, complains about USB port

[pccobbler]

I bought a "refurbished" HP laptop with Ryzen 5 processor a while back. Yes, I know "refurbished" means it was used. It came with minimal resources, so I replaced the memory with new Crucial sticks and replaced the SSD with a new Samsung 970 EVO. I run Devuan Linux on it. Every now and then the boot messages will state that one of the USB 3.0 ports is bad, with that port sometimes being dead, though the next reboot usually makes it work. And sometimes the boot sequence will freeze for a minute or so. The memory passes memtest. When I run gnome-disk-utility, the SMART test option is grayed-out (I would have sworn that internal NVMe drives have that option available, but maybe my recollection is faulty). Running s-tui does not show any processor problems. So the three likely candidates are SSD, processor, or motherboard, but I'm leaning toward the motherboard being flakey due to the USB complaints. Anyone want to guess?