Yes, well if you uninstall HP Support Assistant, the FN + ESC command doesn't work. It is meant to bring up a window similar to this, with all of your information in one place.
Not a big deal, but HP Support Assistant will also keep your drivers up-to-date proactively, if you ever want to reconsider that. I checked on your specifications. You don't have a Power Inverter, so it is just going to be the LED panel itself. That is where I would start, since it doesn't seem to be a video cable issue.
Here is your Maintenance and Service Guide. Display panel replacement starts on page 39. The part numbers are listed at the top of page 39. There are two part numbers listed for each type of display. The one in your computer currently is part number 716399-001. You can run a search on Google for that or you can get it directly from HP at the Parts Store.
Let me know if you have any questions on that! :)