Playstation 3 Won't Display On My TV?

I hooked up the standard red/white/yellow AV cables (no hdmi, that doesn't even plug into my TV), I checked all connections, I put the TV on the correct setting, both devices are apparently working fine, I even made absolutely sure that both devices were turned on. But I just can't get the picture to come up on my screen. Is there some other stupid mistake I'm making?