It wasn’t apparent to me from the pictures, but when reassembling, the exposed metal teeth on the ZR ribbon need to be facing DOWN as you re-insert. Be warned that the ZIF socket will accept it wrong way up, without protest.

In my case, it turned out there was nothing wrong with my speaker… one of the wires that feeds around the screen was bad.

I just managed to install a Seagate BarraCuda 2TB SATA 6Gb/s 128MB Cache 2.5-Inch 7mm Hard Drive (ST2000LM015) in my 2014 Mac Mini. I pre-formatted the new drive, followed steps 1-32 of Mac mini Late 2014 Hard Drive Replacement, and then steps 25-35 of this article.