multipul paper jamb - printer stopped feeding paper

The Epson 680, just like the Epson 1520 series printers have a known
problem with the paper feeders which develops over time, it's most
likely the most common breakdown on those models.

Usually, a new feeding mechanism (just the plastics + springs +
feeding wheel) can be purchased, either via Epson themselves or a
distributor (expensive) or just by picking up a 2nd hand printer of
the same model from eBay (http://www.ebay.com/).

Another option (incase the printer wasn't neglected for too long) is
to disassemeble it manually, clean the paper feeding mechanism, oil
the paper feeding wheel, and give it another try.

Hope it helps!