IBM 5150 - Using BASIC

Error
Description
Diagnostic Action
Row(s)
of
1. Check ribbon for damage (folds, holes,
Print Dots
tears). Replace cartridge
if damaged.
Missing
2.
Verify print head gap adjustment is between
0.6
to 0.65 mm (0.024 to 0.026 in.) at
center position
of adjusting lever. (See
Section 3, "Removal/Replacement.")
3.
Check for damaged platen. Replace print
mechanism
if platen is damaged. (See
Section 3, "Removal/Replacement.")
4.
Check print head for broken wires.
If wires
are broken, replace print head. (See Section
3, "Removal/Replacement.")
5.
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]).
Resistance
=22 ohms?
YES:
Replace both Control cards (see
Section 3, "Removal/Replacement").
NO:
Disconnect print head cable and
check pins I through 9
on print head
cable for approximately 22 ohms in
respect to common. (See Section 5,
"Locations.
")
Resistance =22 ohms?
YES:
Replace Print Mechanism
assembly (see Section 3,
"Removal/Replacement").
NO:
Replace print head (see Section
3, "Removal/Replacement").
1400-20