HP Designjet 4520 Printer series - Manual (Page 131)

Corrective action
1. Check that you are using appropriate print quality settings. See Choose print quality settings
on page 57 .
2. Clean the printheads. See Recover (clean) the printheads on page 97 .
3. Reprint the Image Diagnostics Print. If you still see banding, continue with steps 4 and 5.
4. As there are two printheads for each color, check exactly which printhead is responsible for the
problem, using Part 3 of the Image Diagnostics Print. See
Interpret Image Diagnostics part 3
on page 121 Part 3.
5. Replace the printhead that shows the problem. See Remove a printhead on page 92 and Insert a
printhead on page 94 .
Horizontal bands across all the colored strips
If the printer has paper advance problems you will see horizontal bands across all the colored strips.
NOTE: Banding in the green strips is more difficult to see.
Corrective action
1. Check that you are using appropriate print quality settings. See Choose print quality settings
on page 57 .
2. If you are using low-quality paper, try better-quality paper. The performance of your printer can be
guaranteed only if you use recommended papers. See
Supported paper types on page 200 .
3. Perform paper advance calibration with the same paper type that you intend to use for the final
print. See
How do I... (paper advance calibration topics) on page 125 .
4. If there is no improvement in print quality, contact your customer service representative.
Interpret Image Diagnostics part 3
If part 2 has revealed a printhead problem, the purpose of part 3 is to identify which particular printhead
is faulty. Each rectangle in this plot is labelled with the number of the printhead that produced it.
ENWW Interpret Image Diagnostics part 3 121
Diagnostics