Just moved into house with KitchenAid Trash Compactor Model KUCS180, installed many years ago. Prior owner says it has never been used. Looks unused. I've never used a compactor.

Following the manual, I put about 2/3 full of fairly light stuff in the big drawer, turned key to Start (and tried turning fan to On a few times; there are no other switches), then it makes a noise like what a compactor might sound like (and no odd sounds of machine stress, like grinding), completes its cycle, but when I open the drawer nothing has changed. As if the "ram" doesn't come down.

I'm trying to figure out if I'm doing something wrong, or if I should call a repair person. Thanks for any tips.