Television picture. Hullo there, I have an LG plasma 50 inch but when i turned it on today i

Question

Hullo there, I have an LG plasma 50 inch but when i turned it on today i couldn't see any pictures. I can hear the sound alright but instead of the picture, i only see a mixture of different colours. I tried to switch it off and back on but still the problem persists. I cant even get into the menu on the remote control. It just doesn't show me anything apart from these strange colours. What could the problem be please?