PlayStation 3 AV Cable Help?

It most definitely could be the cables. They are inexpensive, so you could just buy some more and try them out. You could also reset the video connection. When your ps3 is powered down (you see the red light on the front) hold the power button until you hear three beeps. This does a reset of the video connection. You will see a prompt on the the screen when you start it up--this is how you know you did it correctly. There is a another measure you could take if neither of these tips work. Let me know.