Hi ColinT and welcome to the Q&A Forum,
Sorry to hear about the problem with you camera. Unfortunately, it sounds like the LCD needs repair but the only way to know for sure is to contact Sony tech support. When you do, ask them if there has been any service advisory on the camera.
If so, you
may be entitled to a free repair.
If the camera needs a repair, make sure you ask the cost before sending it in. The repair may cost more than buying a new digital camera. Prices for may digital cameras have dropped considerable during the past two years.
Check out our Repair section for additional information:
http://www.digicamhelp.com/camera-care/repair/