@Richie521
Hello;
Allow me to welcome you to the HP forums!
Not much you can do to troubleshoot when there is no display.
You paid for free HP Tech Support as part of the warranty coverage, so you might as well make use of it.
While this PC is still under warranty, you should contact HP Customer Support directly to have them put you in touch with HP Technical Support to see what they can do about troubleshooting and repairing your machine remotely.
I did this recently and the HP Tech was able to remotely access my PC from the Internet and do the needed repairs.
If you live in the US or Canada, contact information is on this page: http://www8.hp.com/us/en/contact-hp/phone-assist.html#section1
If you live elsewhere, contact information is on this page: http://www8.hp.com/us/en/contact-hp/ww-contact-us.html
NOTE: After you get through, stay on the line until you are finally able to talk to some one -- it can take a while!
If you have trouble finding a phone number, then try: 1 (800) 474-6836
Good Luck
I am a volunteer and I do not work for, nor represent, HP