HP C7769B Service Manual - Page 16

Troubleshooting HP-GL/2 color differences in different HP DesignJet Printers Color differences between one image printed on the HP DesignJet 500/800 Series and the rest of the DesignJet platforms are due to the different chemistry of the 500/800 series inks compared with the rest of the inks for other printers. This color variability among different HP DesignJet Series Printers has always been present. To solve the problem, try the following: n Perform the color calibration from the driver at the time of printing. However, that calibration is not very accurate but it may help in the most severe cases. n Some applications have color controls for the user to modify the image in order to obtain the desired colors. n Printing with PostScript reduces the problem significantly. n Avoid very long exposures to extreme environmental conditions after printing with glossy media (more than 12 hours at 80% humidity may result in severe changes in color). Banding at variable extreme environmental conditions Since the Accuracy Calibration has been done at normal environmental conditions, printing in extreme environmental conditions will cause banding because the advance of the Drive Roller does not correspond to the same conditions that the calibration was done in. To solve the problem, try the following: n Perform the Accuracy Calibration in the new environmental conditions (Refer to the User's Guide). 1-6 HP DesignJets 500 and 800 Series Printers Service Manual