Thanks for reaching out to us on HP Support Forums. 🙂 I came across your post and would like to help.
I understand that you have an HP OfficeJet Pro 6970 All-in-One Printer and while scanning or making copies there are two vertical lines.
To provide an accurate resolution, I need a few more details:
Do the vertical lines appear while you're scanning/copying from the scanner glass bed or from the ADF (Automated Document Feeder)?
I recommend you to perform the following steps to isolate the issue and arrive at a fix:
Disconnect the power cable from the printer while the printer is still ON.
Disconnect any other cables if connected the printer.
Press and hold the printer’s power button for 15 seconds.
The printer should be directly connected to the wall outlet and not to a surge protector. Reconnect the power cable to print and the printer should power ON by itself. If the printer doesn’t power ON then please manually power it ON.
If the issue persists then I suggest you to perform the steps as described in detail from this link.
I sincerely hope this fixes the issue. Let me know how it goes. Cheers! 🙂