Hi,
Please connect your laptop to external monitor through HDMI cable and see if lines are appearing in the external monitor.
Is the lines there in BIOS setup? Tap away F10 key as soon as you power on laptop to enter BIOS setup.
If yes,
Then your laptop is covered within 1 year warranty and you still have 5 months left. I'll suggest you to directly contact HP technical support in your region. They would assist you further.
This forum is not official HP technical support. HP maintains no official presence here. All the members helping others here are end users like you.
http://www8.hp.com/us/en/contact-hp/ww-phone-assist.htmlhttp://www8.hp.com/us/en/contact-hp/ww-contact-us.htmlWarranty check:
https://support.hp.com/us-en/checkwarrantyPossibly display panel issue. If it is display connector issue, then lines would come and go during the movement of lid or laptop.
Regards
Visruth