AV cable doesnt work ?

hi,

Yesterday i bought a AV cable for my ipod touch 4g.

When i was home i connected it with my TV but...

when i play a movie , only sound does appear :S.

i dont live nearby a Apple store.

So can someone help me.
Ty

Btw i already searched on google but nothing worked

The AV cable compatible with your iPod, if purchased from Apple, is THIS. If you purchased the older cable, which would be about half the price of this one, it won't be compatible with your iPod.

i have exactly the same but , with 3 plugs ( white , yellow , red ) .

and i purchased it from a apple store

this one : http://store.apple.com/us/product/MC748ZM/A?fnode=MTY1NDAzOQ&mco=MjAyNDI1OTU

Ok, cool. That looks like the correct cable as well. I know on the older iPods, you had to go into settings and tell the iPod to send video to the external source, but the details from the iPod Touch manual are sketchy to say the least. I'm going to defer to someone else for specific troubleshooting here, as I don't have the correct cable for testing.