HP Designjet 4520 Printer series - Manual (Page 132)

Here are three examples of a black rectangle in close-up, showing the fine lines of which it is made:
In the first two examples above, there are so many missing lines that the printhead may be faulty. In the
third case there are only a few missing lines, which are acceptable, because the printer can compensate
for such minor problems.
Corrective action
If part 3 shows a problem with one printhead, but part 2 shows no problem, there is no immediate need
to take any corrective action, because the printer is able to compensate for the problem and maintain
print quality. However, if part 2 also shows a problem, continue as follows:
1. Clean the printheads. See Recover (clean) the printheads on page 97 .
2. If there is no improvement in print quality, replace the printhead that shows the problem. See
Remove a printhead on page 92 and Insert a printhead on page 94 .
If I still have a problem
If the entire Image Diagnostics Print contains no defects and you still experience print quality problems,
here are some things to check:
● Try using a higher print quality option. See Choose print quality settings on page 57 and Change
the print quality on page 57 .
● Check the driver you are using to print with. If it is a non-HP driver, download the correct HP driver
from the Web: see
Update my printer's software on page 116 .
● If you are using a non-HP RIP, its settings may be incorrect. Refer to the documentation that came
with the RIP.
● Check that your printer's firmware is up to date. See Update my printer's firmware on page 116 .
122 Chapter 12 How do I... (Image Diagnostics Print topics) ENWW
Diagnostic
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