IBM 5150 Hardware Maintenance Manual page 155

Error
Description Diagnostic Action
No Printing 8. Measure resistance between pin CN6-l3,
(Driver Circuit card) (see Section 5,
"Locations") and pins CN6-2l, 22,23, and
24 (Stepper Motor Coils) on cable end for
a reading of approximately 45 ohms.
Resistance
=
45 ohms?
YES: Replace Control cards. (See Section 3,
"Removal/Replacement.")
NO: Replace Print Mechanism assembly.
(See Section 3, "Removal/
Replacement. ")
Print Head 1. Go to page 1400-11, "No Printing."
Carriage
Not Moving
1400-14