Alienware M18x 8 beeps at post

I've turned on the laptop and used it for about 15 min when the screen glitched out and part of the right side was appearing on the left. I turned it off and booted in safe mode without a problem starting up again normally same thing happens. Started up in safe mode with networking and it was fine. Started up normally again and same thing but the screen then only displays grey vertical lines which then turned blue (like bsod) screen now no longer shows anything, tried plugging in an external monitor and rebooting I could see boot screen first time now it is also blank and just does 8 beeps with a pause at the end then repeats. I've cleaned out the vents thoroughly just on the off chance it would help. Now I'm stuck with a laptop I can't use. Any suggestions on what to do next would be greatly appreciated, if there is any extra info required please ask, ill be as helpful as I can. Cheers