Apple LaserWriter 12/640 PS - Manual (Page 227)

2 Open the top cover of the printer and remove the toner cartridge. If the jam is around the
pressure roller area, remove the paper as shown here:
If you cannot remove the paper, pull the paper from within the printer, first
pulling into the printer, then out toward you to free it.
3 Remove the paper cassette to see whether the jam is in the paper cassette area. If so,
gently release or pull out the jammed paper.
Check that all paper edges are under the bracket at the front of the cassette.
Paper edges over the bracket are also considered paper jams.
228 Chapter 11