05-26-2017 11:24 AM
Welcome to HP Forums, this is a great place to get support, find answers and tips.
Thank you for posting your query, I'll be more than glad to help you.
I understand that you are facing issues with your HP Officejet Pro 6830 e-All-in-One Printer wherein you get black lines while on the paper while copying or scanning.
This issue could occur if the scanner mechanism is defective or the scanner glass is dirty.
Let's go through a few steps to troubleshoot this issue.
And here's the step by step guide for you in the link: Fixing Copy Quality Issues
Let me know how this works.
You have a good day ahead.