HP 750 - Manual (Page 210)

10-12 C4705-90000 Product History and Service Notes
Problems that Cause Paper Advance Errors
Date: 1 February 1996
Service Note: C3195AĆ02A
C3196AĆ02A
C3198AĆ01A
Supersedes: C3195AĆ02
C3196AĆ02
C3198AĆ01
Products: HPDesignJet 750C (C3195A)
HPDesignJet 750C (C3196A)
HPDesignJet 755CM (C3198A)
Serial Numbers: C3195A ESA0000000/ESA5B05350
C3196A ESA0000000/ESA5B20304
C3198A ESA0000000/ESA5B02306
To be performed by: HPĆQualified Personnel
Parts Required:
Part Number Description Qty
C3195Ć60142 Paper Advance Kit 1
Situation
There are two main problems that generate paper advance errors:
Problem 1 Ć AVION" Ć Back tension
One problem has been found when the plotter finishes a plot, advances the paper, cuts it and
then rewinds to plot the next one. In this process, the paper roll itself is not rewound and
thus there is a portion of paper which has been unrolled for cutting.
The high paper back tension produced by the brake of the rollĆfeed module causes the XĆaxis
motor worm to bend slightly just at the moment when it starts to pull the paper from the roll
and thus resulting in a one off swath error. This phenomena is called AVION" and looks very
similar to a Banding" phenomena.
This phenomena occurs only once at the beginning of the print. This band is normally located
between 65 and 75 mm from the top border of the paper.
Problem 2 Ć Rollcover screws / spindle interaction
The spindle spacer or the spindle itself can interfere with the screws of the rollĆfeed covers.
This can cause some paper advance errors which appear as bands on the image prints.