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HP Designjet 4500 Printer Series - Image Diagnostics Print

Printing the Image Diagnostics Print

The Image Diagnostics Print consists of patterns designed to highlight print quality problems. It helps the user to check whether there is a print quality issue. If there is an issue, it helps understand the cause and provides information to resolve it.
note:
Before using the Image Diagnostics Print, ensure that the appropriate print quality settings are being used.
To print the Image Diagnostics Print:
  1. Ensure that at least A3 size paper (29.7 × 42 cm = 11.7 × 16.5 inches) has been loaded into the printer. Use the same paper type that was being used when the issue was detected.
  2. Ensure that the front panel has the same print quality settings that were being used when the issue was detected. In the Image Diagnostics Print, the only difference between 'Drawings/text' and 'Images' is that the latter uses more ink in part 2, so that the colors appear darker.
    Printing the Image Diagnostics Print will take about two minutes if 'Images' is chosen. Choosing 'Drawings/text' might sometimes takes less time (depending on the paper type).
  3. At the printer's front panel, select the (printer) icon, then select Internal prints followed by Image diagnostics prints and then Print drawings/text or Print images.
    Figure : Internal Prints menu
  4. When the print is ready, refer to the next section:

Responding to the Image Diagnostics Print

The Image Diagnostics Print is in three, numbered parts.
  1. Part 1 tests printhead alignment. Click here to go to Interpreting Image Diagnostics part 1.
  2. Part 2 tests printhead performance and the paper advance mechanism. Click here to go to Interpreting Image Diagnostics part 2.
  3. If Part 2 has revealed a printhead problem, Part 3 identifies which of the eight printheads is responsible for it. Click here to go to Interpreting Image Diagnostics part 3.
    note:
    If Part 2 has not revealed any problem, ignore Part 3.

Interpreting Image Diagnostics part 1

The purpose of part 1 is to identify color-to-color alignment and bidirectional alignment problems.
Figure : Image Diagnostics part 1
Figure below displays horizontal misalignment:
Figure : Horizontal misalignment
Figure below displays vertical misalignment:
Figure : Vertical misalignment
Figure below displays bidirectional misalignment:
Figure : Bidirectional misalignment

Corrective Action

  1. Align the printheads using the same paper type with which unacceptable print quality was experienced.
    note:
    some paper types are not suitable for printhead alignment.
  2. If there is no improvement in print quality, contact the customer service representative.

Interpreting Image Diagnostics part 2

The purpose of part 2 is to test whether the printheads and the paper advance mechanism are working correctly. This part of the print should not be used to check for color consistency or accuracy.
Figure : Image Diagnostics part 2
Banding
Banding is said to have occurred when the user can see repetitive horizontal bands within the printed image. They can appear as light bands:
Figure : Light bands
They can also appear as dark bands:
Figure : Dark bands
They can also appear as a more gradual, wave effect:
Figure : Wave effect

Horizontal bands across strips of one color only

If a printhead is faulty, the user will see horizontal bands across strips of one color only; or at least the horizontal bands will be much more noticeable in one color than in the others.
note:
Banding in the green strips is more difficult to see and it may be caused by a yellow printhead or by a cyan printhead. If the user can see banding only in the green strip, it is caused by a yellow printhead. If the user can see banding in the green and cyan strips, it is caused by a cyan printhead.
Figure : Horizontal bands across strips of one color only

Corrective action

  1. Ensure that appropriate print quality settings are being used.
  2. Clean the printheads.
  3. Reprint the Image Diagnostics Print. If banding still persists, 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.
  5. Replace the printhead that shows the problem.

Horizontal bands across all the colored strips

If the printer has paper advance problems, the user will see horizontal bands across all the colored strips.
note:
Banding in the green strips is more difficult to see.

Corrective action

  1. Ensure that appropriate print quality settings are being used.
  2. If low-quality paper is being used, try better-quality paper. The performance of the printer can be guaranteed only if the recommended papers are used.
  3. Perform paper advance calibration with the same paper type that is intended to be used for the final print.
  4. If there is no improvement in print quality, contact the customer service representative.

Interpreting 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 labeled with the number of the printhead that produced it.
Figure : Image Diagnostics part 3
Here are three examples of a black rectangle in close-up, showing the fine lines of which it is made:
Figure : Black rectangle
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.
  2. If there is no improvement in print quality, replace the printhead that shows the problem.

If print quality issues persist

If the entire Image Diagnostics Print contains no defects and if the user still experiences print quality issues, try the following solutions:
  • Try using a higher print quality option.
  • Check the driver being used to print. If it is a non-HP driver, click here to go to http://www.hp.com/go/designjet/ and download the correct HP driver.
  • If a non-HP RIP is being used, its settings may be incorrect. Refer to the documentation that came with the RIP.
  • Ensure that the printer's firmware is up to date.
  • Ensure that the user has the right settings in the software application being used.
  • If there is a problem only at the top of the page, the user can try the following solutions to resolve it:
    1. The easiest solution is to select the Extended Margins option in the driver, the Embedded Web Server, or the front panel. This means that the area of the paper affected by the problem (at the start of the page) will no longer be printed on.
    2. Align the printheads.
    3. Ensure that the appropriate print quality settings are being used.