Just fixed the same problem on my apple laserwriter 16/600 tonight. The gear that goes from the drive assembly (from the motor and running the front half of the paper flow) to the fuser is on a pivot. Mine was pivoted up a bit, and so wasn't making good contact. It had been making noise for the last 20 prints or so, but then finally lost contact.
Pivoting that gear down, so it contacts the metal gear on the fuser assembly, made it now work.
It seems like there should be a spring holding it in this position, or that the toner cartridge should hold it down. But on mine it doesn't. Unfortunately I spent 4-6 hours figuring this out, and taking apart the printer, before figuring out that the gears just weren't making good contact. But I cleaned out a piece of scorched paper and the 2 sensors on the fuser, and cleaned out 18 years of dust, so something was accomplished.