Epson LQ-2550 User Manual page 191

7. Remove the shield plate above the parallel interface by pressing in on
the plastic clips located at the back of the plate. (The following
illustrations show a rear view of the printer.)
8. Remove one of the screws labelled CG (chassis ground) from the
main board. The illustration shows you the location of the CG screw
that you should remove.
Using Printer Options
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