** perhaps a blown fuse somewhere **
There is no fuse in the freezer itself. If you have power at the outlet, the only fuse for it (in your house fuse panel) must be Ok.
** The thing was last plugged in about two years ago but was working at the time. **
Can you hear the compressor running?
If not, it could be just a wire off somewhere, you'd have to trace the wiring to see if you can find it. (The wiring on freezers is pretty simple.)
If the compressor is running but the unit is not cooling, the freezer is likely out of refrigerant and now likely not worth repairing.
From the Useful Freezer Tips from the 'Home Service' section of my site linked below:
Do not leave your freezer unplugged for a lengthy time. The condenser coils welded inside the cabinet are made of steel, while running they are kept hot evaporating moisture. When not operational, they are exposed to the moisture and rust out. The refrigerant gas then leaks out and major repairs are required.
The Appliance Information Site
[This message has been edited by DanO (edited December 31, 2002).]