IBM 4247, Maintenance Information

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Print Quality Failures (Darkness, Location, Quality) Action
Vertical print line misalignment (lines move upward,
page-to-page).
1. Install a new upper feed roller.
2. Install the latest level paper bail assembly with the improved
spring arrangement. The latest level paper bail has 2 blue
tabs on the left end cap; the older has 1 tab.
Vertical print line misalignment. [Lines move downward on the
rear path as much as 1mm (0.039 in.) following the first page
after initial load.]
1. Check the operation of the pinch rollers.
2. The rear forms path is not the same as the front forms path.
Rear path registration is affected by the 180 degree turn the
path makes around the platen. On the front path, paper
passes straight through the printer. Print line registration on
the rear path can change by up to 1mm after the initial load.
This small change in registration might be objectionable to a
customer using pre-printed forms if characters print outside of
a box.
The solution is to raise the print 1mm higher on the first page
by raising the load position. This will keep the print inside the
box on all pages.
Registration-critical jobs, where a small change is not
acceptable, should be run on the front path.
Fanfold paper print line skew. Print line too high or low at one
end of line. See “Paper Path Service Checks” on page 301.
Single sheet feed print line skew. Print line too high or low at one
end of line. See “Manual Sheet Feed Path Check” on page 317.
Chapter 1. Diagnosing Problems
148