HP Latex 1500 User guide - Page 419

You may see the alert Automatic Printhead Alignment cancelled because of scanning errors, which can be caused by different problems: ● The scans of the printed blocks cannot be performed reliably on the current substrate. The scans of the patterns maybe unreliable or impossible on substrates that are non-white, transparent, or translucent, or have a very rough or punched surface. For these substrates, automatic printhead alignment using the builtin line sensor may not be possible. ● Some patterns of the automatic printhead alignment plot are defective due to: - Stains or printhead crash marks on the substrate that can be easily seen by visual inspection of the three blocks in the plot. Make sure the substrate has no stains before running automatic printhead alignment. - Printhead crash marks may occur when the substrate is wrinkled. See There are wrinkles and ink smears on the substrate on page 369 - Generally poor print quality due to clogged nozzles. See Check and clean the printheads on page 122. ● Either the built-in line sensor is not working properly or is not well calibrated. Automatic printhead alignment uses the black colorant as reference to align the rest of colorants, therefore the line sensor has a specific calibration that saves the proper distance between the line sensor and the black printhead (see Print Care diagnostics on page 154). If the LsToK (line sensor to black) calibration is not done, it can be seen by a visual inspection of the plot. In this case, the black patch is overlapping the spitbars of the first block of patterns, shown here: If the problem persists, call your service representative (see HP Customer Care Centers on page 416) Printhead cleaning roll errors You should not touch the printhead cleaning roll except when you need to replace it. When the printhead cleaning roll reaches its end, it should be replaced. Always do this by following the Internal Print Server wizard. See Printhead cleaning roll on page 122. Any handling of the roll may prevent the printer from keeping track of roll usage, in which case you may see spurious error messages, and a printing job may be cancelled unnecessarily. ENWW Printhead cleaning roll errors 411