SO. I wanted to update. I have now replaced the RAM temporarily with a single stick of 8GB from Timetec, “premium”… whatever. Point is, I just removed it from the packaging, installed it, and tried to boot the server. It still went straight to the GRUB menu I mentioned in my initial post. So, I stuck the USB drive with TrueNAS installation media on it, and attempted to reinstall the software, and guess what? Same errors. “Unable to enumerate USB device.”
I am currently running memtest86 again with the new RAM installed in order to rule out a defective out of box RAM stick.. but then just now read a recent post saying “memtests are pointless” which has confused me even further… Here: PSA: "Memtests" are pointless - #5 by winnielinnie
So. I will report with the results in the morning but, it’s been running for over an hour and I’ve had zero errors.
Important to note, I have also tried multiple USB flash drives, and tried multiple USB ports when attempting to re-install TrueNAS. Same outcome, every time.
At this point I’m actually feeling like smashing my server with a hammer and starting over. Motherboard? CPU? What the actual hell..? Is it possible I had faulty RAM AND a faulty CPU, or motherboard? How would I go about troubleshooting the next most likely thing?
I’m sorry guys. Thank you for your input, so much.