IBM PCjr Hardware Maintenance And Service page 202

1. Rotate the leadscrew drive gear to move the print
head to it's left-most position.
2. The resistance on the CNH connector should be
within the range listed below.
3. Measure this resistance now.
Pin 1 to Pin 2
Print Head
Low Ohm High Ohm
0 2
WERE YOU ABLE TO READ THE CORRECT
RESISTANCE?
NO The print mechanism is bad. Replace it. Repeat
the advanced test to ensure that the IBM PC
Compact printer is operating correctly.
3-850-14 Compact Printer