IBM 5150 - Page 164

Error
Description
Diagnostic Action
Extra 3.
Measure resistance between pins CN
6-1 to
Print
9 (see Section 5, "Locations") with respect
r"'-
Dots
to every other pin.
Any pin shorted together?
NO:
Replace both Control cards (see
Section 3, "Removal/Replacement").
YES:
Disconnect print head cable and
recheck pins CN
6-1 to 9 with respect
to every other pin.
Any pins shorted together?
YES:
Replace Print Mechanism
assembly (see Section 3,
"Removal/Replacement").
NO: Replace print head (see
Section 3, "Removal/
~
Replacement").
Printing
1.
Position Printer Power switch to OFF.
Continues Check continuity
of End-of-Forms switch
Beyond End-
from pin CN 6-18
on Driver Circuit card
of-Forms (see Section
5, "Locations") to the ground
pin
on Driver Circuit card; open when forms
inserted and shorted when forms removed.
Replace Print Mechanism assembly
if switch
fails (see Section 3, "Removal/
Replacement").
2. Check for +5 V dc at CN 6-18 on Driver
Circuit card (see Section 5,
"Locations")
with forms inserted. Check power supply if
,--... ,
oV dc. Use ground pin on the driver card.
Doublespacing
1.
Replace both Control cards (see Section 3,
•
or Abnormal "Removal/Replacement").
Characters
1400-23