I've always kept the old machine, renovated it two years ago. I use it for storage, and processing things with Handbrake. It was flaky and I thought it was time for a new Debian install. But it was randomly turning off.
I installed the basic fine, but it wasn't transferring files well. Then I poofed it up to 'unstable' or sid. And while it was doing that, I forgot and started to stream a movie. A wonderful thunderstorm, and it was bricked.
It powered up nice, but nothing on the screen, and no life on the network. Blah, it is impossible to to diagnose, wouldn't take a live Debian usb. I'm giving up and moving the disks to the main machine. I'm keeping the newish power supply, and other things. Back to just one main machine.
I like the small-format machines but I also like big 3.5 inch 4tb disks. So, I'll just trundle along.