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Scanner troubleshooting

In this section the most common defects and failure modes are shown, sorted by relevance and frequency of appearance.

A defect is a common image artifact that usually appears when using any CIS scanner. These are due to incorrect settings, product limitations, or easily solvable mistakes. A failure mode is due to malfunctions of some of the scanner components.

Some of the corrective actions proposed here require the use of the scanner diagnostic plot, which you can print and scan as indicated in Scanner diagnostic plot. Do not use any printed version of this guide to test the scanner, as the resolution of the images included here is insufficient. Use the diagnostic plot when recommended in response to any of the errors described in this chapter.

You are recommended to clean the CIS sensors at first installation, and at any time for good scanning quality.

Random vertical lines

The following steps provide the complete procedure for this topic.

This is one of the most common issues in sheet-fed scanners. Usually, the vertical streaks are caused by dust particles inside the scanner, or miscalibration of the scanner (in these cases, the problem can be solved). Here are some examples of images suffering from vertical lines or streaks. Note the black arrow indicating the scanning direction in these examples.

Random vertical lines
  1. Clean the scanner's glass plate and the original to be scanned as described in Clean the scanner’s glass plate. Re-scan your original afterwards.

  2. If the streaks remain, recalibrate the scanner as indicated in Calibrate the scanner. Make sure you clean the maintenance sheet before calibrating the scanner, and check that the maintenance sheet is not damaged (if so, call your support representative and ask for a new maintenance sheet). Re-scan your original after the calibration is completed.

  3. If the streaks still remain, check the scanner's glass plate visually. If it is damaged (scratched or broken), call your support representative.

  4. If the streaks remain, there may be dust particles inside the glass plate. Carefully take out the glass plate and clean it as described in Clean the scanner’s glass plate.

Note:

The problem of vertical streaks cannot always be solved, due to the technological limitations of CIS technology. HP offers HD Scanners with CCD technology for higher quality requirements. If the streaks remain after the corrective actions explained above, then no further action can be taken to improve the image quality, except to buy a more expensive CCD scanner.

Wrinkles or folds

The following steps provide the complete procedure for this topic.

Scanners based on CIS technology have a high optical resolution within their focus plane, at the price of a very limited depth of field. Hence, the images are sharp and detailed when the scanned original is perfectly flat against the glass plate. However, whenever the original contains wrinkles or folds, these defects are clearly visible in the scanned image (as shown in the following example).

Wrinkles and folds
  1. Re-scan the original, setting the content type to Image, and contrast and background cleaning to zero.

  2. If the problem persists, re-scan the original at a lower scanner resolution (Standard quality if scanning, Fast or Normal if copying). It may also help to flatten the original manually as much as possible before scanning it again.

Note:

The problem of wrinkles cannot always be solved, due to the technological limitations of CIS technology. HP offers HD Scanners with CCD technology for higher quality requirements. If the wrinkles remain after the corrective actions explained above, then no further action can be taken to improve the image quality, except to buy a more expensive CCD scanner.

Line discontinuities

The following steps provide the complete procedure for this topic.

When scanning or copying large originals, you may sometimes find issues such as that shown in the following image, where a straight line (it does not necessarily have to be horizontal) appears with discontinuities or small steps. Note the black arrow indicating the scanning direction in this example.

Line discontinuities
  1. Repeat the scan, preferably using a higher resolution, and this time make sure that the product is correctly positioned (it is flat on the floor and it does not move), and that the printer is not printing while you scan. Turning the original 90 or 180 degrees and scanning it again may also solve the problem.

  2. If the problem persists, check that the original to be scanned is not skewed, and that it does not become skewed during the scan. If so, see Incorrect paper advance, skew during scanning, or horizontal wrinkles. You might also want to deactivate the automatic de-skew algorithm as indicated in Copied or scanned image is very skewed.

  3. If there is no skew but the problem persists, clean and calibrate the scanner as indicated in Scanner maintenance. Take care not to move the printer during the calibration (the printer should not be printing during scanner calibration), and check that the maintenance sheet is correctly positioned before starting the calibration. Also check that the maintenance sheet is not damaged before calibrating the scanner (an old or damaged maintenance sheet may cause this problem); if it is damaged, call your support representative and ask for a new maintenance sheet.

  4. If the problem persists, proceed to analyze the following areas of the diagnostic plot:

    1. 4 (from module A to E).

    2. 10, at the intersection between modules.

    3. 13 in modules A and E, and 14 in modules B, C, and D.

    If you see any of these defects in the studied areas, call your support representative and report a "line discontinuities" error after calibration.

The four vertical thin black lines at the beginning and the end of the diagnostic plot show, approximately, the position of the intersection between CIS modules, where this kind of error usually appears. If the error appears outside these areas, call your support representative and report "line discontinuities within a CIS module".

Small color differences between adjacent CIS modules

The following steps provide the complete procedure for this topic.

When scanning wide plots, sometimes slightly different colors can be seen at both sides of the junction between two CIS modules. This issue, if present, can be easily seen by analyzing patterns 9 of the diagnostic plot at the intersection between CIS modules. Here are some examples. Note the black arrow indicating the scanning direction in these examples.

Color differences between CIS modules, diagnostic image

Sometimes the color mismatch between adjacent modules can be enormous, showing a serious scanner malfunction, as in the following example.

Color differences between CIS modules, bad diagnostic image
  1. Repeat the scan or copy, setting the content type to Image, reducing the background cleaning to 0 or turning the original 90 degrees before scanning it again.

  2. If the problem persists, clean and calibrate the scanner as indicated in Scanner maintenance. If calibration ended without errors, proceed to analyze again pattern number 9 and modules A through E of the diagnostic plot.

  3. After analyzing pattern 9, if you see some color differences between left and right sides of the bars for neutral and vivid colors, call your support representative and report "small color differences between adjacent CIS modules".

Variable line thickness or missing lines

The following steps provide the complete procedure for this topic.

When scanning some CAD plots at Standard resolution, mostly when working with grayscale or black-and-white prints that contain very thin lines, you may see a variation in line thickness, or even some missing lines, in some places:

Variable line thickness
  1. Repeat the scan or copy using a higher resolution (High or Max if scanning, Normal or Best if copying). You should also set background cleaning to 2, or set the content type to Mixed. You might also deactivate the automatic de-skew as explained in Copied or scanned image is very skewed. In case you were working in black-and-white mode, we recommend using grayscale instead.

  2. If the problem persists, turn the original plot 90 degrees before scanning it again.

  3. If the problem persists, clean and calibrate the scanner as indicated in Scanner maintenance.

Inaccurately reproduced colors

The following steps provide the complete procedure for this topic.

You have to deal with several variables if you want perfect color matching between the original you are scanning and the copy or scanned file you obtain as a result. If you find undesired colors in cases like the example shown below (original on the left, scanned image on the right), you can follow these guidelines.

Color inaccuracy

Actions:

  1. Make sure that you choose the correct paper type in the scan settings before scanning.

  2. When dealing with copies, you must take into account that good color matching between a given original and its copy can be achieved only if both are printed on the same type of paper. In the case of scanned files, good color matching can be achieved only if your monitor is color-calibrated or compliant with sRGB or AdobeRGB standards.

  3. If the above conditions are met, you should also take into account that various scanner settings can affect the final color result, such as contrast, background cleaning, content type and paper type. To obtain the best possible colors, set contrast and background cleaning to 0, set the content type to Image, and select the most appropriate type of paper according to the original you are scanning (if in doubt, use photo paper).

  4. Note that the image enhancement settings are automatically reset to default values after a certain time, so you may get a different result from copying the same original if you have not checked the settings before starting the job.

  5. If you scanned to a PDF file, try opening the PDF file in Adobe Acrobat and saving it as a PDF/A file. For more information, see http://www.adobe.com/products/acrobat/standards.html (English only).

  6. For optimum color results, clean and calibrate the scanner as indicated in Scanner maintenance.

  7. Avoid placing the scanner in direct sunlight or near sources of heat or cold.

Color fringing

The following steps provide the complete procedure for this topic.

The problem called "color fringing" occurs when the scanner is affected by incorrect paper advance and/or miscalibration. Nevertheless, some amount of color fringing is unavoidable, especially at high scanning speeds. It can be seen at the borders of sharp black text over a white background, as in the example below (original on the left, scanned image on the right). Note the black arrow indicating the scanning direction.

Color fringing
  1. Repeat the scan after increasing the scanner's resolution (choose Max quality if scanning, Best if copying). Turn your original 90 degrees, if possible, before scanning it again.

  2. If the problem persists, clean and calibrate the scanner as indicated in Scanner maintenance. Repeat the scan at a high resolution (Max if scanning, Best if copying) and check whether the problem disappears.

  3. If the problem still persists, you can diagnose this issue by analyzing the patterns 6 and 8 (A to E) of the diagnostic plot. The black horizontal lines appear slightly colored at the top and bottom of each end (in the example on the right, below). Normally, they look red at the top and blue or green at the bottom, but it could be the other way around.

    Color fringing, diagnostic image

    If you see this effect, call your support representative and report "color fringing problem after calibration".

Vibration

The following steps provide the complete procedure for this topic.

If your printer is not properly placed on a flat surface, or if the scanner lid does not close correctly, you may sometimes find that the scanned image suffers from vibration, as in the following example: original on the left, scanned image on the right.

Image affected by vibration
  1. Make sure that the scanner is placed on a flat surface, the scanner lid is correctly closed, and the printer is not working while you are scanning. Scan your original again.

  2. If the problem persists, change (increase or decrease) the scanning resolution and re-scan your original. We also recommend turning the original 90 degrees before scanning it again.

  3. If the problem persists, analyze pattern 4 of the diagnostic plot. If you see the problem shown on the right, call your support representative and report a "vibration problem".

    Vibration, diagnostic image

Incorrect paper advance, skew during scanning, or horizontal wrinkles

The following steps provide the complete procedure for this topic.

You may encounter problems with some thick glossy originals being moved through the scanner's paper path. In some cases, the original may become skewed during the scanning process.

If some of the paper rollers are not working correctly, you may find small horizontal wrinkles in the scanned image, due to the paper being stuck in some regions while not in others.

  1. Turn your original 90 degrees and repeat your scan.

    Important:

    Do not hold the paper while it is being scanned.

  2. If the problem persists, open the scanner lid. Clean the motor wheels (small gray rubber) and the pressure rolls (wide white plastic). Check that all the pressure rolls can move freely. If you find dust particles or objects that obstruct the movement of the rollers, try to remove them, then close the scanner lid and repeat your scan.

  3. If the problem persists, restart the scanner by turning it off and on again. If you find an error message on the front panel during this operation, call your support representative and report the error message. If no error message appears, try repeating your scan.

  4. If the problem persists, analyze patterns 4, 13 and 14 of the diagnostic plot. The plot should look like this:

    Paper advance OK
  5. If you see an image resembling the incorrect examples below, call your support representative and report an "incorrect paper advance" problem.

    Paper advance not OK

Vertical black band 20 cm wide

The following steps provide the complete procedure for this topic.

Your scanner contains various different CIS modules, each of which covers an area 20 cm7.9 in wide. If one of the modules fails, and the scanner hardware check does not detect the failure, you may see a black vertical band, corresponding to the area covered by a single CIS module, in your scanned image or copy.

Here is an example: original on the left, scan on the right. The black arrow indicates the scanning direction.

Image affected by vibration
  1. Open the lid of the scanner and check that the five CIS modules show blinking red, green and blue lights alternately. If a module is failing, call your support representative and report a "CIS module illumination" error.

  2. If all the modules lit up correctly in the previous step, restart the scanner by turning it off and on again. If you find an error message on the front panel during this operation, call your support representative and report the error message. If no error message appears, try repeating your scan.

  3. If the problem persists, try to calibrate the scanner as indicated in Calibrate the scanner. If this operation fails, call your support representative with the error code given on the front panel. If no error code appears, try to repeat your scan.

  4. If the problem persists, call your support representative and report a "vertical black band 20 cm wide".

Scanner damages some originals

HP is aware that this scanner may cause vertical scratches on inkjet originals on thick glossy paper. Very thin tracing paper or old originals may also be damaged. This is because CIS technology requires the original to be held down with high pressure to obtain accurate results and avoid blurring and defocus problems.

If the original you intend to scan is valuable, and if it belongs to one of the types described above (inkjet-printed, thick, glossy original or old/thin/tracing paper original), HP recommends using a CCD scanner such as the HP DesignJet T1200 HD MFP.

Object replication (ghosting)

The following steps provide the complete procedure for this topic.

This error very rarely appears in CIS scanners. However, you can occasionally find image defects like the following: original on the left, scanned image on the right.

Image Ⓒ www.convincingblack.com, reproduced with permission.

  1. Restart your printer. Then calibrate the scanner, as indicated in Calibrate the scanner, and repeat your scan. Turn the original 90 degrees if possible before rescanning.

  2. If the problem persists, analyze pattern 3, modules A through E, of the diagnostic plot. Call your support representative and report an "object replication" issue if you see the kind of error shown on the right.

Clipping or incorrect scale factor when down-scaling in copies and prints

When doing copies or prints (from USB, or printer driver), the scaling setting is available with various possible options. If you are experiencing problems related to border clipping, or it seems that your print has lost the scale-factor adjustment, read this section carefully in order to select the best value for the scaling setting in future jobs.

  • Precise scaling: In this case, the content of the original image is scaled by the percentage factor that you have selected. For example, in an original CAD image with a 1:100 scale, if user selects scale to 50%, the printed plot will have an accurate scale of 1:200. Nevertheless, in the case of down-scalings when selecting a fixed percentage, some clipping of the marginal content of the plot may occur, as it is impossible for the printer to print up to the borders of the paper.

  • Scale to fit into page size: In this case, the content of the original image is scaled by the percentage necessary to make sure that all the content is correctly printed and no clipping occurs. Nevertheless, in the case of down-scalings when selecting fit to page, the scale-factor adjustment may not be an integer divisor of the original. For example, in an original CAD plot with a 1:100 scale on A2 paper size, if user selects scale to fit on A3 paper size, the scaling factor will not be exactly 50% and the scale of the printed plot will not be 1:200 exactly. However, the plot will be printed completely without clipping any content.

Incorrect edge detection, mostly when scanning tracing paper

The following steps provide the complete procedure for this topic.

Tracing or translucent papers can be scanned with good results, although totally transparent papers are not supported. Nevertheless, the resulting image may have extra margins or some clipping of the content in some situations when detection of the edge of the paper is not accurate, which may also happen when scanning plain paper if the glass plate is dirty. In order to avoid these undesired effects, follow these recommendations.

  1. Carefully clean the scanner's glass plate and the original to be scanned with a cloth. Turn the original 90 degrees if possible and re-scan it afterwards. Remember to select Translucent as the paper type at the scanner if your original is translucent.

  2. If the problem persists, calibrate your scanner, and re-scan your original again afterwards.

  3. If the problem persists in the case of translucent paper, attach a sheet of white paper to the back of the original to be scanned. Remember to select White paper as the paper type for the scanner in this case.

Copied or scanned image is very skewed

Originals are often loaded into the scanner with some degree of skew. In order to correct for this unavoidable problem, the scanner has a built-in automatic de-skew algorithm, which measures the skew in the original and rotates the scanned image so that the result is perfectly straight. However, in some cases the de-skew algorithm may increase the skew rather than correcting it. In other cases, the skew is so bad that it cannot be automatically corrected.

To load the original with minimum skew, grasp the original with the image facing up and your hands at left and right edges. You are recommended to avoid resting your hands or the original on the scanner's input tray. Push the original into the scanner insertion slot until you feel the whole top border of the original pressing against the scanner rubber rolls, which will load the original after a delay of 0.5 seconds. Now you can take your hands off the original. If you are not happy with the way the scanner has grabbed your original, you can tap Eject icon and try again.

The action of the automatic de-skew algorithm can be deactivated by tapping Copy icon, or Scan icon. Select the quickset to use, then tap more settings and disable the de-skew setting.

Cannot access the network folder or HP SmartStream (if installed as an accessory)

The following sections provide details for this topic.

If you have set up a network folder, but the printer cannot access it, try the following suggestions:

  • Check that you have filled in each field correctly. See Configure a network folder.

  • Check that the printer is connected to the network.

  • Check that the remote computer is switched on, working normally and connected to the network.

  • Check that the folder is shared and that you have the correct permissions and functionality use of it.

  • Check that you can put/read files (depending of the functionality use), to the same folder from a different computer on the network, using the printer's logon credentials.

  • Check that the printer and the remote computer are in the same network subnet; if they are not, check that the network routers are configured to forward the CIFS protocol traffic (also known as Samba).

Scanning to file is slow

The following steps provide the complete procedure for this topic.

Scanning large formats creates large files. This means that scanning to file can take time even under optimal system configurations and conditions. This is especially true when scanning across a network. However, if you think scanning to file with your system is unreasonably slow, the following steps may help you to locate and solve the problem.

  1. Use the front panel to check the status of your scan job. If it is taking an intolerably long time, you can select the job and then cancel it.

  2. Check that the Resolution setting is right for the job. Not all scanning tasks require high resolutions. If you lower the resolution, you will speed up the scanning process. For JPEG and PDF scan jobs, you can also change the Quality setting. Lower quality values produce smaller files.

  3. Check your network configuration. Your network should be a Gigabit Ethernet or one of a higher transfer rate in order to achieve optimal scanning speeds. If your network is a 10/100 Ethernet configuration, you can expect slower transfer of the scan data and thus slower scanning speeds.

  4. Contact your network administrator for information about your network configuration, transfer rates, scan-to-file destinations on the network and possible solutions for increasing the speeds.

  5. If scanning to files on the network is too slow and the network configuration cannot be amended to correct this, improved speeds can be achieved by scanning to a USB flash drive.

  6. If scanning to a USB flash drive seems slow, check your USB flash drive interface compatibility. Your system supports a Hi-Speed USB interface. Your USB flash drive should be compatible with Hi-Speed USB (sometimes known as USB 2). Also check that your USB flash drive contains enough storage space for scanned large-format images.