IBM Infoprint 1130, Service Manual

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Diagnostic Information
2-117
IBM Infoprint 1130/1140
Print Quality - Banding
Service Tip: Banding is difficult to detect except on a page with a
uniform gray or a large amount of graphics printed on the page.
Banding is primarily due to a variation in the speed of the paper as it
feeds through the printer, especially in the development and transfer
process. Inspect the alignment assembly, main drive assembly and
all other paper feed components for signs of wear, dirt, binds, or
damage, especially the drive gears. Banding appears as light or
dark horizontal lines on a uniformly gray page.
Banding can also be caused by a defective charge roll brush contact
or HVPS. Check the charge roll contact for any signs of damage and
for proper connection to the HVPS and print cartridge.
Print Quality - Black bands on outer edges of the page.
This print quality problem appears as vertical black bands on one or
both sides of the copy and can be wide, narrow, light or dark.
FRU Action
1 Charge Roll
Counterbalance Springs If the problem is just on one side of
the page, check the charge roll
counterbalance spring on that side.
You can check to see if enough force
is being applied to the charge roll by
applying a slight downward pressure
with your finger to the charge roll link
arm that the spring is attached to
while you run a print test sample.
See if the problem changes or goes
away. If this fixes or changes the
problem, then check the springs and
charge roll link arm assemblies for
binds or defective parts. Replace as
necessary.