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.
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
 
						

							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 printers 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 printers firmware is up to date. See 
Update my printers firmware on page 116.
122 Chapter 12   How do I... (Image Diagnostics Print topics) ENWW
Diagnostics
 
						

							●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 recommended papers (see 
Supported paper types on page 200).
●Abnormal but stable environmental conditions: if you are printing in unusual conditions of
temperature or humidity (see 
Environmental specifications on page 210), and those conditions
are expected to remain stable, recalibration may be worthwhile.
However, paper advance calibration assumes that you have an image quality problem and that you have
already followed the appropriate troubleshooting procedure for that problem. If you have no particular
problem, there is no need to perform the calibration.
Before performing paper advance calibration, use the Image Diagnostics Print to check that the
printheads are correctly aligned (see 
Print the Image Diagnostics Print on page 118).
NOTE:In theory, paper advance calibration should improve print quality. However, if you find the
calibration print difficult to interpret, you may choose the wrong paper advance setting and thus degrade
print quality. In this case, you can restore the original factory settings by selecting the 
 or  icon at
the front panel, and then Paper advance calibration > Optim. for drawings/text or Optimize for
images > Select Pattern > Factory Default.
●Overview of the calibration process
●
The calibration process in detail
●
After calibration
Overview of the calibration process
1.Use the front panel to print a colored pattern stored in the printer seven times, each time with a
different paper advance setting.
2.Decide which pattern has been printed most successfully.
3.Use the front panel to tell the printer which pattern was best—and therefore which paper advance
setting to use in future.
NOTE:There are separate paper advance settings for each paper type name in the front panel: each
must be calibrated separately. When you calibrate a particular paper type, the settings for all other paper
types are unaffected.
ENWW Overview of the calibration process 125
Paper advance
calibration
 
						

							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
Step 1. Load the printer with the type of paper that you plan to use for printing subsequently. The paper
must be at least 41 cm wide (16 in) and 75 cm long (30 in).
Step 2. At the front panel, highlight the 
 or  icon. If you are using an HP Designjet 4520 series
printer, and you have two rolls loaded, make sure that the roll you intend to calibrate is ready to print (it
should be highlighted on the front panel).
Step 3. Press the Select key, then Paper advance calibration.
Step 4. Select Optim. for drawings/text or Optimize for images, depending on the type of prints you
wish to make subsequently.
NOTE:It is very important to use the same setting that you will later use for printing in the driver, the
Embedded Web Server or the front panel (Optimized for drawings/text or Optimized for images).
Otherwise the calibration has no effect.
Step 5. Select Print Patterns. The printer will print a series of numbered patterns (1 to 7), each looking
like this if you selected Drawings/text:
or like this if you selected Images:
The Optim. for drawings/text print takes about three minutes, the Optimize for images print takes
about five minutes. When the calibration print has finished printing, the printer will cut the paper.
Step 6. Look at each of the printed patterns (1 to 7) and decide which one shows the best quality. Each
pattern has one part on the left that is a continuous color gradient (A), and another part on the right (B).
Either part can be used to help you decide which is the best of the series of patterns; it will depend on
your circumstances. However, if you are using glossy paper or canvas, you are recommended to ignore
part A and make your selection by looking at part B only.
126 Chapter 13   How do I... (paper advance calibration topics) ENWW
Paper advance
calibration
 
						

							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 following scenario descriptions may help you.
●Where you have only one pattern which is clearly the best and the ones above and below contain
light/dark bands, select this pattern.
ENWW The calibration process in detail 127
Paper advance
calibration
 
						

							●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 appears lightest, most uniform and least grainy.
Step 7. Select the 
 or  icon, and then Paper advance calibration > Optim. for drawings/text
or Optimize for images > Select pattern.
Step 8. Select the number of the pattern (1 to 7) that printed best. If you found it difficult to choose
between two patterns e.g. patterns 3 and 4, then select “Between pattern 3 and 4”.
The calibration is complete.
After calibration
If you find that the paper advance calibration has reduced but not eliminated your print quality problem,
you could try step 7 again and select a different number. If you are seeing light bands, try selecting a
lower number than your original selection; if you are seeing dark bands, try a higher number.
If you later want to cancel your calibration and restore the paper advance setting with which the printer
left the factory, select the 
 or  icon, and then Paper advance calibration > Optim. for drawings/
text or Optimize for images > Select pattern > Factory default.
128 Chapter 13   How do I... (paper advance calibration topics) ENWW
Paper advance
calibration
 
						

							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 printer unloads the paper while switched off [4520]
●
The printer unloads the paper when switched on [4520]
ENWW129
Paper problems
 
						

							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 paper path to the platen, it may be that the leading edge of the paper
is not straight or clean, and needs to be trimmed. Remove the initial 2 cm (1 in) from the roll and
try again. This may be necessary even with a new roll of paper.
●Check that the spindle is correctly inserted. The spindle lever on the right should be in the horizontal
position.
●Check that the paper is correctly loaded on the spindle, and that it loads over the roll towards you.
●Check that the paper is wound tightly on the roll.
Sheets
●Check that the leading edge of the sheet is aligned with the cutter channel in the platen.
●Do not use hand-cut sheets, which may be of irregular shapes. Use only purchased sheets.
Here is a list of front panel messages related to paper loading, with the suggested corrective action.
Front panel messageSuggested action
Right edge of roll too far from load line.The roll has not been loaded correctly, the right–hand edge was not aligned
with the half–circle on the platen. Press the Select key to try to load the roll
again.
Right edge of sheet too far from load
line.The sheet has not been loaded correctly, the right–hand edge was not aligned
with the half-circle on the platen. Press the Select key to try to load the sheet
again.
Right edge not found.The printer cannot locate the right–hand edge of the paper, the paper may be
badly positioned. Press the Select key and try to load the roll again.
Sheet edge not found.The printer cannot locate the edges of the paper, the paper may be badly
positioned. Press the Select key and try to reload the sheet.
Paper not found.During the paper load process the printer did not detect any paper. Press the
Select key to retry.
Paper loaded with too much skew.During the paper load process the printer detected that the paper had too much
skew. Press the Select key to try to load the paper again.
Paper too small.During the load process the printer detected that the paper is too narrow or too
short to be loaded in the printer. Press the Cancel key to stop the load process.
See 
Functional specifications on page 208.
Paper too big During the load process the printer has detected that the paper is either too
wide or too long (sheet only) to be loaded properly. Press the Cancel key to
stop the load process. See 
Functional specifications on page 208.
130 Chapter 14   The problem is... (paper topics) ENWW
Paper problems