Specifications

4–27Troubleshooting
Diagnostic Self–Tests
Run diagnostic self–tests to check the print quality and operation of the
printer. The self–tests are listed below; the procedure for running the tests is
explained on page 4–29.
NOTE: Under the description of each diagnostic test is a list of items that
may require adjustment or replacement if the test produces a bad
print pattern. Items are listed in the order they should be checked:
simplest items first, moving to more complex components.
ASCII Swirl A sliding alphanumeric pattern useful for identifying
missing or malformed characters, improper vertical alignment, or vertical
compression.
Ribbon
Splined shaft skew adjustment
MPU sensor
Hammer spring
Hammer coil
All E’s A pattern of all uppercase letter Es useful for identifying missing
characters, misplaced dots, smeared characters, improper phasing, or
light/dark character variations.
Ribbon
Splined shaft skew adjustment
MPU sensor
Hammer spring
Hammer coil
E’s plus TOF A pattern of all Es followed by a form feed to the next
page top of form, useful for identifying paper motion or feeding
problems.
Power supply board
Mechanism Driver board
Paper motion sensor
Paper feed belt or motor
Splined shaft bearings
Tractors or tractor belts
All H’s A pattern of all uppercase letter Hs useful for detecting missing
characters or dots, smeared characters, or improper phasing.