My Cash Drawer Won't Pop

The cable that runs from the cash drawer to the back of the printer may be in the wrong port on the printer. This one's happened a few times. The printer has an Ethernet port in the back of it for use cases where you're just hooking it up to a computer network as opposed to a computer, and the cables have similar ends. The cable for the drawer can be jammed into it if someone is intent enough. The cable should have a little resistance before it clicks into place, but you shouldn't have to force anything. Verify it's in the right port on the printer and give it another go.