PS gets no picture or flashes green pixely mess.

When I start my PS I get no picture, just a black screen. Then sometimes it will blink this green pixelated screen that looks like whatever webpage I'm on on my computer (I use my TV for my computer screen). I looked at the Sony website but their support page isn't helpful. Anyone know whats going on?

did you recently change the cables you were using that cannot get the same HD format you were using? Do you get sound?

Nope, I haven't changed anything. I just turned it on today like I normally do. I was just playing last night with no problems. I don't get any sound. I've also tried different games and still I get the same result.