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HP Printer & All-in-One Products - Communication Error Messages Are Displayed on the PC and Printout Looks Garbled or Shows Unexpected Symbols


Defective communication between your computer and your HP printer or All-in-One product can result in manifold symptoms, being the most common of them:
  • Printout looks garbled or shows unexpected symbols (e.g. smilies, hearts or squares).
  • Pages are picked up and ejected blank.
  • There is no response from the printer when a print job is sent.
  • Communication error messages are displayed on the PC screen, for example:
    • Bidirectional communication cannot be established
    • Printer out of paper
    • Error writing to LPT1/USB00X due to an unknown system error (being "X" any digit between 1 and 9)
    • Error writing to LPT1/USB00X. Unknown parameter
    • Print cartridge incorrectly installed
    • Print cartridge not recognized


Proceed with the steps below to solve this issue:
  1. Disconnect the USB or parallel cable from the rear of your printer or All-in-One product, and print a self-test report to check if the unit is working fine in standalone mode, and hence discard any hardware issue.
    The user guide provided with your printer contains instructions for printing a self-test report in standalone mode.
    If the self-test report cannot be printed, the cause of the issue is hardware-related (not covered by this document). Please, check if your printer shows any error message (or warning light blinking) and consult the product manual for solution.
    If the issue remains unsolved, enter the HP Customer Care site for support.
  2. Reconnect the parallel or USB cable and try printing again. If printing is successful the cause of the issue may be a loose parallel or USB cable.
  3. Disconnect the power cord from the rear of the printer or All-in-One product, wait for a few seconds, and reconnect it. Restart your computer and try printing again.
  4. Make sure no external devices are sharing the USB or parallel port with your printer or All-in-One product (e.g. USB hubs, storage devices, etc...). Remove any external devices, and connect the printer or All-in-One product directly to a USB or parallel port on the rear of your computer.
  5. Make sure the cable is not too long (it should be shorter than 3 meters for parallel cables, and 1,80 meters for USB cords).
    High-speed USB cables are labeled as USB 2.0 certified.
  6. Check if there are any devices around the USB or parallel cable that can cause electromagnetic interferences (these devices may be fluorescent or incandescent lamps, radios, TVs, cordless phones, wireless routers, microwaves or speakers). If there are any of such devices near the cable, power them off and restart the print job.
  7. Make sure the printer or All-in-One product is not connected to a power strip or surge suppressor. Other devices connected to the same power strip may cause power fluctuations.
  8. If the issue persists, disable bidirectional communication between the printer and the computer. Click here to learn how to disable it.
  9. If your printer or All-in-One product is connected through a parallel port, make sure the following requirements are met:
    • The parallel cable must be IEEE-1284 compliant. This standard provides a better protection against electromagnetic interferences.
    • The parallel port mode must be set to ECP (Extended Capabilities Port).
      The parallel port mode can be checked from the device manager on your computer.
      However, in order to change the parallel port mode it is necessary to access the BIOS (Basic Input/Output System).
      Consult the documentation provided with your computer or contact the manufacturer to learn how to access the BIOS on your computer.
  10. Uninstall the HP software, download the latest version of the software, and install it on your computer again.

Disabling bidirectional communication

Bidirectional communication permits the printer to send status information (e.g. cartridges ink level) to your computer.
Follow the steps below to disable this capability:

Windows XP

  1. Open the Startup menu, and select Printers and Faxes.
  2. Right-click the icon for your printer to open the contextual menu, and select Properties. The printer properties window opens.
  3. Select the Ports tab, uncheck the Enable bidirectional support option, and then click the OK button.

Windows Vista

  1. Click the Windows icon () on the Windows taskbar, and select Control panel.
  2. Depending the Windows Vista View configuration, browse through the appropriate path:
    • Vista: Under the Hardware and sound () category, click the Printer link.
    • Vista Classic: Double-click the Printers icon ().
  3. Right-click the HP printer icon () to open the contextual menu, and then select Properties.
  4. Select the Ports tab, uncheck the Enable bidirectional support option, and then click the OK button.






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