Facing TV Problems? Ask a TV Technician.
Hello and sorry you're having problems. Offhand, half of the screen going black generally points to a hardware failure occurring in the TV. In a Plasma this is caused by the Buffer Boards, and in an LCD this is caused by the Backlight Circuit, or power supply.
In order to provide more specifics, can you please postback with the full model number off of the back of the TV as well as how long you've owned it for please?