I'm trying to connect my ps3 to my at&t S-Video set in the back of the ps3 and I managed to get sound out of it using another RedYellowWhite cord so i just need video, my yellow cord is broken btw. PS. MY AT&T DEVICE IS A U-VERSE CABLE BOX, IT HAS 2 SETS OF PLACES TO PUT THE REDYELLOWWHITE CORDS AND A S-VIDEO PLUG IN AND OTHER USELESS STUFF, FYI........
The Red and White cables transfer the sound, which would explain why you've received it. If your Yellow is broken though you're going to need some new RCA Composite Cables (that's what they're called). Plugging just the Red, White, and S-Video cables WILL give you a picture (most likely), but the picture will be very distorted and won't play right. So yeah, solution: Get some new cables. You can probably get them at a fair price off of eBay or Newegg.
Then you've got to buy some new cables. I could see living without the Red or the White cord, because those are Audio, but the Yellow transfers Video. And I'd suggest getting a cable with an S-Video as well, it isn't a huge difference in quality, but it will make the text of your video a lot sharper. I'm assuming that it's just your PS3 RCA cables that are broken, in which case just go down to Gamestop and find them. If you really need help ask someone. They might even have them at a larger store like Best Buy, but they could overcharge you. I just recently bought this new at a Gamestop near me for $13. It has S-Video, and will connect to a PS2, PS3, Wii, and XBOX 360, so if your box is going to be used for multiple game systems, you can plug the RCAs into there from this cord, and then just change the end for the game system. This could also help you out, if you can use it. It'll improve the color as opposed to the standard RCA cables.