HP Designjet L26100 HP Designjet L26500 / L26100 printer series - Maintenance - Page 63

Troubleshoot images ● If bands affect only some colors, the cause could be a defective printhead. ◦ Print the printhead status plot (see Use the printhead status plot on page 54). If necessary, clean the printheads (see Clean (recover) the printheads on page 18). ◦ Clean the printheads again. ◦ Align the printheads (see Align the printheads on page 9). If necessary, align them manually. ◦ Print the printhead status plot again. Identify the printhead with the greatest number of blocked nozzles, and replace it. ◦ If bands appear and disappear intermittently, go to the front panel and select the icon, then Image quality maintenance > Enable extra PH cleaning. Remember to disable this option when you no longer need it, because it shortens the life of the printhead cleaning kit. ● If bands affect most of the colors, the printheads could be misaligned. This is likely if you have not aligned the printheads for a long time, or if there has been a substrate jam. Align the printheads if necessary (see Align the printheads on page 9). You can check whether it is necessary by using the printhead status plot (see Use the printhead status plot on page 54). ● If banding occurs mostly in black areas, create a new color profile using pure black and not a mixture of other colors. See your RIP documentation. If the problem persists, call your service representative (see the User's guide). Adjust the substrate advance The substrate advance sensor measures the advance of the substrate and compensates for irregularities at every pass of the printheads. However, to fine-tune the quality of your print, you may need to calibrate the rate at which the substrate advances. The substrate advance determines the placement of dots on the substrate. If the substrate is not advanced correctly, light or dark bands appear in the printed image and the grain in the print may increase. You can modify the substrate advance with the Substrate Advance parameter in the RIP's substrate preset. 1. On the front panel, select the icon, then select Image quality maintenance > Substrate advance calibration > Print adjustment plot. The printer prints a substrate-advance adjustment image. 2. The calibration image consists of several columns with a number at the bottom of each one. Locate the lightest of the columns and enter its number into the RIP's Substrate Advance parameter for the current substrate preset. The value chosen in this example should be "-6". ENWW Horizontal banding 57