Sound only over AV cable?

So I've had my ps3 hooked up to my TV with an HDMI to av adapter, which has been not great. got told today that the ps1 AV cable is compatible with the ps3, so I plugged it in, but I only get sound. I know that the cable works because I've used it with my ps1. is my ps3's av out just damaged or am I missing something?