Hi guys and girls

Just started to watch top gear on my 42" LG lcd tv, and it started flickering really fast and making a strange buzzing noise inside. I switched it off and back on again, it worked for a few seconds, then started doing the same. Then the picture went off completely, although the sound still works. I've left it off for a while longer, put it back on, and its back to the flickering. Tried it using the ps3, and it does the same, so not input related.

Help please


Rich