Alienware Alpha HDMI no Signal

I have a alienware alpha computer which has been working like a dream until a few days ago when all of the sudden I started getting no signal from my HDMI out port. I have tried few trouble shooting ideas such as different monitors, hooking up to tv, changing HDMI cable. none of these seam to work. the computer works fine because I am able to access folders on the pc from the network. but I cannot get any type of signal from HDMI port.  this is extremely frustrating because I can't use the computer because it only has a HDmi out port for a monitor or TV. can someone please help me.