Okay, time to put everything back together. I screwed the drives into the cage, screwed the cage into the case, but before I screwed the cover back onto the case, I turned on the computer just to make sure everything was still okay. A colleague of mine happened to stop by as I was doing all this to discuss a technical matter, and we chatted about the problem while I sat on the floor with a screwdriver. I said to my colleague right before I turned the computer on, “Look, I bet it won’t work.”
Lo and behold, the computer didn’t work. It just made a horrible beeping sound.
Screwing the computer parts back together is the most dangerous step in computer assembly because once you do that, there’s a pretty good chance that something will stop working.
— Raymond Chen, Screwing the computer parts back together is the most dangerous step
This is why I like tool-free cases 
