Hi ... I've just rejoined this list after some years absence. I have an HP dv4 also, with a similar display problem. It's pretty common, broken wires in the cable through the hinge: http://h30434.www3.hp.com/t5/Notebook-Operating-Systems-e-g-Windows-8-and-Software/pavillion-dv4-laptop-screen-problem/td-p/276552 Thanks, Geoff Chesshire