IBM Personal Computer AT Manual To Operations page 150

Setup for Printer Self-Test
19
Tum your printer's power off.
20
Open the access cover.
21
Turn DIP (Dual In-line Package) Switch 10 off
by pushing the switch lever toward the rear of
your printer with the point of a ball-point pen.
Off
t
Switch 10 Lever
1-40 Color Printer