MacDermid ColorSpan 5440 Technical Training Manual - Part Viii. Troubleshooting

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                 

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