There is a black cover plate that slides over the exposed pully and belt behind the jointer fence. I’ve never noticed it before, but it is loose and it was rattling a bit when I used the jointer, which is how I discovered it.
(Actually it’s not loose. It’s not even connected. It just slides in and out loosely.) The cover plate has two holes on one end that looks like they should be used to attach it to the underside of the fence, but I couldn’t really see how.
I pushed all the away in and turned on the jointer and it made a loud noise, like it had caught one of the teeth of the outside jointer blade, but I couldn’t see any nicks on the blades. I pushed it back out so that it just covered the pulleys, turned the jointer back on and it worked normally for me as I finished jointing my board.
What is that black plate and how is supposed to be connected to the jointer?