ellie 0 Light Poster

I've had my monitor for 2 years and it's worked fine until a few days ago. A black line goes across the screen and then the monitor goes blank if i disconnect it from the power supply and reconnect it'll come back on but its getting more frequent. I.v try ed the monitor on another computer and it's the same is it time to get another one or is it something really simple???

Cheers

Ellie