Kodak 800 SERIES service manual Banding Differences, Hardwaresoftware

NovaJet 800 Series Service Manual

Banding Differences

Consistent horizontal banding is usually hardware related. Normally horizontal microbanding is caused by improper color deadband or color calibrations, dirty cartridges or service station. Inconsistent banding is usually software related. However, electrostatic discharge (ESD) from media (i.e. Backlit/Duratrans films) can also cause inconsistent horizontal banding. While minimal microbanding in an image typically occurs due to cartridge jet failures and clogs, dirty service station or an improper calibra- tion of the printer, gross microbanding can be caused by a dirty encoder strip causing image skew or real hardware failures.

Vertical banding is always hardware related. Diagonal banding could be either hardware or software.

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Figure 3-10. Examples of Horizontal Banding.

Hardware banding is usually characterized by consistent banding strips as shown. Typically horizontal banding is caused by the cartridge or print head in 95% of the cases. It signifies a slippage in the media’s normal movement that is possibly due to the stepper motor, lower drive shaft assembly, pinch rollers, or the rollguides on the back of the printer. All these possible faulty areas deal with a rotational movement that, if faulty, will generate a consis- tent banding pattern. The Main PWA and Carriage PWA can also cause this type of error to occur.

Software banding is characterized by inconsistent banding lines or lines which violate the page layout (extend beyond the print border). These

Maintenance 3-17