HP Designjet 4520 HD User Manual

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 121Part 3....

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...

●Check that you have the right settings in your software application.
●If you are seeing a problem only at the top of the page, see 
A defect near the start of a print
on page 154.
ENWWIf I still have a problem 123
Diagnostics
 

124 Chapter 12   How do I... (Image Diagnostics Print topics) ENWW
Diagnostics
 

13 How do I... (paper advance calibration
topics)
Your printer was calibrated at the factory to ensure that it advances the paper accurately when using
supported paper types in normal environmental conditions. However, you may find it useful to recalibrate
in certain circumstances:
●Unsupported paper: different paper manufacturers provide papers with a wide range of properties
such as paper thickness or stiffness, which may benefit from calibration. You can expect the best
print quality when using HPs...

NOTE:There are separate paper advance settings for Optimized for drawings/text and Optimized
for images: each must be calibrated separately.
NOTE:Papers from different manufacturers may require different paper advance settings even if they
are of the same type, therefore the calibration will be useful only for the particular paper you calibrated.
Remember that, when you perform the calibration, you will overwrite any previous paper advance
settings for this paper type.
The calibration process in detail...

In the color gradient, part A, you should look for light or dark horizontal bands (banding), which indicate
that the paper advance is not quite right. Usually you will see dark bands across the first pattern and
light bands across the last pattern (see the examples below). The best pattern is one with no banding;
if in doubt, select the pattern in the middle, between the last pattern with dark bands and the first pattern
with light bands.
If you find it difficult to identify the best pattern, the...

●Where you have two patterns next to each other which do not show signs of banding, see below,
use the patterns above and below these two to help you select. For example, if the pattern above
the two equal ones contains less banding then choose the pattern just below it.
●Where you have three patterns which show no signs of banding, select the middle pattern.
If you look at part B of the print, you will probably see that it appears darker in some patterns than in
others. The best pattern is the one that...

14 The problem is... (paper topics)
●The paper cannot be loaded successfully [4020]
●
The paper cannot be loaded successfully [4520]
●
A paper jam (paper stuck in the printer) [4020]
●
A paper jam (paper stuck in the printer) [4520]
●
A paper jam in drawer 2 [4520]
●
Prints do not stack properly in the bin
●
The printer uses a lot of paper to align the printheads
●
The paper moves while the printer is in standby mode [4520]
●
The printer unloads or trims the paper after a long period of disuse [4520]
●...

The paper cannot be loaded successfully [4020]
NOTE:This topic applies to the HP Designjet 4020 Printer series only.
●The paper may be loaded at an angle (skewed or mislocated). Check that the right-hand edge of
the paper is aligned with the half-circle on the right-hand side of the platen and, particularly in the
case of sheet paper, that the leading edge is aligned with the metal bar in the platen.
●The paper may be crumpled or warped, or may have irregular edges.
Rolls
●If the paper gets stuck in the...