Why do I have no av output?

hi i recently purchased a 60gb ps3 from a friend though now i am having some problems with it. everytime i turn on the ps3 i am getting no picture or sound at all and all i get is a black screen apart from a couple of times my tv has flickered and i get a green distorted screen with the ps3 error message this ps3 was not turned off properly though when i try to press x on my controller i get no response. i have tried everything i can think of including different cables and different tvs and also resetting the console or tring to get into the recovery menu to no avail. i dont know what to do with it now so if someone could please help it would be greatly appreciated.