IBM PCjr Hardware Maintenance And Service page 306

Error
Description
Diagnostic Action
Extra
1. Run "Offline Diagnostic Test" (see page
Print Dots
3-1400-33). Examine the / and Y —
characters for extra dots.
2. Remove CN6 on driver circuit card. See
Section 5, "Locations." Measure
approximately 22 ohms between pin
CN6-10 (male side), and each head coil pin
(CN6-1 to 9 [male side]).
Does the resistance = 22 ohms?
YES: Replace both control cards. See
Section 4, "Removal/Replacement
and Adjustments."
NO: Disconnect print head cable and
check pins 1 through 9 on print head
cable for approximately 22 ohms in
respect to common. See Section 5,
"Locations."
Does the resistance = 22 ohms?
YES: Replace print mechanism
assembly. See Section 4,
"Removal/ Replacement and
Adjustments."
NO: Replace print head. See Section
4, "Removal/Replacement and
Adjustments."
Graphics Printer 3-1400-21