Screen goes black on startup when laptop plugged in

[crzydee]

Hi tech guys, hope someone can help here...
I have an HP pavillips dv6 that I frequently hook up to my TV with my HDMI cable to watch videos, play music, etc. My problem is, the only way the computer will extend the desktop to the TV is to have it plugged in and charging. I also have the oposite problem when I am trying to use my computer without the TV; I cannot boot my computer while it is plugged in or the screen goes black after the welcome screen. Now I am no computer geek over here, but I am guessing it is because of my graphics card it is a RAEDON GRAPHICS AMD.
Can someone help me??

 

[Route44]

How old is this laptop?

 

[crzydee]

I bought it in march 2011 at future shop

 

[Route44]

Then this should still be under warranty. We strongly suggest you take advantage of your warranty and have them fix it.