Hi
Welcome to the HP Forums!
This is a wonderful place to converse with the community, get assistance and find tips.
I reviewed your post and understand that the printer is printing only half page.
Don’t worry, I’d love to help!
In order that I may provide you with an accurate solution, I will need a few more details.
- When was the last time the printer was working fine?
- Are you able to make a copy?
- What is the operating system you are using?
- Have you made any software or hardware changes on the computer?
- Have you performed any troubleshooting steps before posting?
Meanwhile, if the issue doesn’t happen when you make a copy, I recommend you uninstall and reinstall the printer and check.
If the issue happens even when you make a copy then contact HP phone support to check the available service options for your printer.
Let me know how it goes. Awaiting your reply!
To simply say thanks, please click the "Thumbs Up"button to give me a Kudos to appreciate my efforts to help. If this helps, please mark this as “Accepted Solution”as it will help several others with the same issue to get it resolved without hassles. Take care now and have a splendid week ahead.
Good day! Take care 
Cheers!