IBM 5100 Maintenance Information Manual page 196

• Light printing:
The copy control dial might not be set correctly.
Refer to the 5103 MIM (301).
The ribbon might need to be replaced.
- The clearance between the platen and the print
head might be too large. Refer to the 5103 MIM
(360).
There might not be enough tension on the two
print head springs. There should be 700 to 900
grams of tension at the tip of the print head near
the print wires. This measurement should be taken
with the platen removed and the print head near
the center of the machine.
3-114
Check for mechanical binding, sticking, or
interference that would keep the print head from
moving all the way forward toward the platen.
Especially check to ensure that the print head
cable does not interfere.
The ribbon might not be advancing. Check for
broken ribbon drive lines, defective drive clutches,
and misalignment of the ribbon drive gears.
Check to ensure that the ribbon feed roll release
knob is in the proper position. Refer to the 5103
MIM (301).
If one end of the printed line is darker than the
other, check the A-frame alignment. Also check
for a bent platen shaft. Refer to the 5103 MIM
(333).
• If every other line prints light:
- One of the ribbon drive lines might be broken.
Refer to 5103 MIM (301).
- One of the ribbon drive clutches might be
defective. Refer to the 5103 MIM (302).
• If the left margin is uneven:
- The left margin might be set incorrectly. Refer to
the 5103 MIM (343).
Check the adjustments of the print emitter and the
print emitter pickup. Refer to the 5103 MIM (302,
340, and 341).
• If all the print wires fire in the left margin area:
Replace the print emitter pickup. Refer to 5103
MIM (302 and 341).
If part of the character in print position 1 is missing:
The left margin might be set incorrectly. Refer to
the 5103 MIM (343).
- Check the adjustments of the print emitter and
print emitter pickup. Refer to the 5103 MIM (302,
340, and 341).
• Broken print wires:
- The following might cause breakage of the print
wires:
a. Improper setting of the copy control dial for the
thickness of the forms used.
b. Printing over the perforations, the feed holes, or
the edge of the forms.
c. Ribbon jams, which can cause the print wires to
catch on the ribbon and break the wires.
Ensure that fixes or engineering changes for
ribbon jams are installed.
• If the print head carrier stops when it approaches the
right side:
Ensure that the belt clamp does not contact the
print head stepper motor when the print head
carrier is moved to the extreme right. Refer to the
5103 MIM (302).
• If the 24 Vdc supply voltage is too high:
Replace card AlA 1 and the transistor
Q
1. Refer to
the 5103 MIM (303).