Part VIII. Troubleshooting
Some troubleshooting techniques have been mentioned in passing in the preceding sec-
tions. This section points to other documents that may be of use or discusses additional
topics and techniques.
LVDS Errors
LVDS errors are discussed in Tech Note 2735.
Carriage motion failures
Carriage motion failures are discussed in Tech Note 2734.
Vertical Banding
Vertical banding is discussed in Knowledgebase article 10048,
Identifying Sources of
Vertical Banding.
Ink Overfills
An ink overfill occurs when the printheads are, for one reason or another, over-filled with
ink, causing the ink to travel into other parts of the printer, specifically the air vacuum/
pressure system. Recovery from an overfill involves three steps:
1. Clearing ink from the air system. If the ink has reached the air valve/manifold as-
sembly, the assembly must be replaced. The air tubing may discolor from ink contact,
but does not necessarily require replacement. In extreme cases the ink could reach
all the way to the vacuum assembly, requiring replacement of that component as
well.
2. Isolating the cause of the overfill. Most ink overfills occur when there is erroneous
data fed to the printer by the ink/air thermistors in the printheads. (See Section V for
a detailed description of the thermistor system.) In some cases, damage to the head-
board (e.g., during improper reinstallation) could lead to a similar effect. In even rarer
cases, a defect in the printhead reservoir allows a good set of thermistors to report
inaccurate information.
To determine if the thermistors are the cause (which is most likely), remove the
thermistors from the printheads so they are exposed to air, leaving them connected
to the headboard. A perfectly-matched triplet of thermistors should have same value
when all three are actually in air. If an ink thermistor has slightly higher value than its
air thermist or, that is acceptable; but an ink thermsitor in air that reads lower than its
air thermistor opens the possibility for ink overfills of the printhead.
5400 Technical Training Manual
MacDermid ColorSpan Confidential
Page 35 of 39
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