(From: Jim Steel (firstname.lastname@example.org).)
The power supply is encased in a bonded 2-piece ABS plastic housing. There is a fuse inside but no way to access the fuse without splitting the case.
Splitting the case:
Unplug the power supply and secure the power supply in a utility vice. Use a short-blade utility knife or linoleum knife to slowly and carefully and cut along the seam where the 2 halves of the power supply are joined. Don't try to cut the seam all at once. Work a little at a time until the case halves can be separated.
Replacing the fuse:
On a power supply with an unsoldered fuse socket, simply replace the fuse and test the power supply. Alternately, a leaded fuse may be soldered in.
On a power supply with the fuse soldered into the fuse socket, leave the fuse in the socket and solder in a leaded fuse. (A leaded fuse has lead wires extending from each end of the fuse.)
On a power supply with a leaded fuse, unsolder the old fuse solder in a new leaded fuse.
Testing the power supply:
Ensure that the power supply and printer work before bothering to close the case.
Closing the case:
ABS plastic cement may be used to bond the power supply case halves. Alternately, electrical tape may be used to hold the case halves together.
Note: also see the chapter on Photocopiers as the operation and problems of the two types of equipment are very similar.