envy7640 only prints top half of a line for every few lines printed

[BB12341234]

My ENVY 7640 only prints the top half of every 4th or 5th line printed

[A4Apollo]

Hi! @BB12341234, Thanks for stopping by HP forums!

I understand your printer is printing only top half line for every few lines.

Don't worry I'll try to help you out.

Did you make any changes to your printer?

Try making a copy from your printer and check if the issue persist.

Please try the steps recommended below.

Try performing a performing a power wash on your PC and check if it helps.

Note: All data saved on your device hard drive (local storage) is deleted when you use Powerwash. Back up all important files, either on the Web or with an external storage device, before resetting the device.
Click the status area of the taskbar, and then click Settings.
Scroll to the bottom of the Settings page and click Show advanced settings.
In the Powerwash section, click Powerwash.
Click Restart to begin resetting the Chromebook.

Refer this document to know more information about performing power wash on your chromebook.

Also, Refer this article to further troubleshoot print quality issues.

Let me know if this helps!

Have a beautiful day ahead! 🙂