Test plot lined print on MK only

[StevoMc]

I have the HP T770 which has started missing lines when plotting in B+W

I printed the in machine version of Kung Foo panda plot and it plots fine.

When printing a B+W CAD drawing its missing lines, i printed a test plot and its only the MK

I have replaced with the MK cartridge, cleaned the printheads and carried the machine a printhead clean

Could it be the printhead? before i fork out £85 on a new printhead, has anyone had a similar issue?

Many thanks

[Meghana_10]

@StevoMc, Welcome to the HP Support Community. 

Thanks for reaching out about your query regarding the HP T770 printer. 

We're thrilled to have the opportunity to assist you and provide a solution. We hope our assistance has been helpful! 

It seems like you are experiencing issues with missing lines in black-and-white plots from your HP DesignJet T770, specifically related to the Matte Black (MK) printhead. Here are some steps and considerations before investing in a new printhead:

Troubleshooting Steps:

1. Verify Media and Settings:

   • Ensure you are using media compatible with black-and-white printing and that your printer settings are optimized for the selected media type.
   • Double-check the print quality settings in your CAD software to ensure they match the printer's capabilities.

2. Printhead Cleaning Procedure:

   • Perform a thorough printhead cleaning from the printer's menu. It's possible to run multiple cleaning cycles if one doesn't resolve the issue.
   • Check for any obstructions or dried ink around the printhead area.

3. Printhead Alignment:

   • Execute a printhead alignment process, which can help if the printhead is misaligned, causing lines to miss.

4. Nozzle Check:

   • Print a nozzle check pattern to identify if certain nozzles are clogged or not firing correctly.

5. Software and Driver Update:

   • Ensure that your printer drivers and firmware are up to date as software updates can fix bugs and improve printer performance.

Troubleshooting Missing Lines on HP T770

It seems like you are experiencing issues with missing lines in black-and-white plots from your HP DesignJet T770, specifically related to the Matte Black (MK) printhead. Here are some steps and considerations before investing in a new printhead:

Troubleshooting Steps:

1. Verify Media and Settings:

   • Ensure you are using media compatible with black-and-white printing and that your printer settings are optimized for the selected media type.
   • Double-check the print quality settings in your CAD software to ensure they match the printer's capabilities.

2. Printhead Cleaning Procedure:

   • Perform a thorough printhead cleaning from the printer's menu. It's possible to run multiple cleaning cycles if one doesn't resolve the issue.
   • Check for any obstructions or dried ink around the printhead area.

3. Printhead Alignment:

   • Execute a printhead alignment process, which can help if the printhead is misaligned, causing lines to miss.

4. Nozzle Check:

   • Print a nozzle check pattern to identify if certain nozzles are clogged or not firing correctly.

5. Software and Driver Update:

   • Ensure that your printer drivers and firmware are up to date as software updates can fix bugs and improve printer performance.

Community Insights:

• Similar Issues: Many users have reported similar issues attributing them to a faulty printhead or incorrect cartridges. Community forums often suggest double-checking cartridge compatibility and firmware versions.
• Cost Consideration: Before purchasing a new printhead, consider whether a thorough diagnostic or professional service could pinpoint the issue more precisely.

When to Replace the Printhead:

If you have exhausted the above troubleshooting steps and the issue persists, there might be damage or functional failure in the MK printhead. Replacement would then be a reasonable step to take:

1. Purchase from a reliable vendor to ensure the printhead's authenticity.
2. Follow the installation instructions carefully when replacing the printhead to avoid damage or improper setup.

Replacing a printhead can indeed fix line production problems when printing, especially if other troubleshooting methods fail. However, it's crucial to ensure these steps have been carefully and fully executed to rule out simpler fixes.

I hope this helps!

Take care and have an amazing day! 

If you would like to thank us for our efforts to help you, go to the public post and give us a virtual high-five by clicking on "Yes" for the question "Was this reply helpful?" below my message, followed by clicking on the "Accept as solution" on my public post.

Regards,

Meghana