How do i fix my screen that is half black

Welcome to the Dell Community @lyric1 

Sounds like a cold solder joint on the display.

The only way to repair is to replace the display.

Please post the exact model of your laptop, if you need help to find a replacement???

Best regards,

U2

Hi @lyric1  welcome to this user to user discussion forum. This is not Dell Support. 

Seems the screen cable is not fully seated in its motherboard socket. You could reseat this cable, or if under warranty, raise a product support fault ticket, or Reject new system if less than 30 days old and get a replacement or a full refund. 

lyric1,

To accurately assist in troubleshooting and finding the correct parts, reply to the DELL-Cares private message with the PC Service Tag number.

So a display replacement is needed. Take it to anywhere that specializes in the repair of Alienware laptops and a part that is compatible with your system.