MY LG LED TV ISSUE

[Slimztee]

Two days ago I was busy watching my TV with my son and suddenly the screen went blank whilst it was still producing sound. I thought he had pressed a button on the remote control that made the screen go blank, but all I did to make come back on prove futile. Is this a problem peculiar with such TV? I can't even call the company as it is well over 3 years old and the warranty is expired. What can I do?