Can I fix my Television, picture only displays on the middle third?

I have a Bush 28" Widescreen TV that up until recently has been fine. The picture now only displays in the middle third of the screen. The height of the display is as normal, but the width of the screen has been compressed into the middle. Changing to the different display modes does nothing to image it stays exactly where it is. All external cables have been pulled out and put back in. All AV channels connecting to external devices have been checked, but nothing changes the size of the image on the screen.

Is it possible to fix this, if so how? Am I looking at having to buy a replacement :-(

Thanks for your responses (if I get any)