watching downloaded movies on large TV ?

I have a powerbook G4 . 15" with OS x 10.4.11 and i want to watch downloaded movies on a 36 inch Sanyo television. I have bought the mac audio cable to plug into headphone jack on laptop with the RCA audio connections for the TV.. and I have the mac DVI to S.Video or RCA video jack.. using the S.Video cable but I can not get the movie to show on the large TV.. I have the TV set on Video 1 .. but I must have to do something on the laptop to make is show?
What is it I do..?
Thanks

did you turn off both the TV and the powerbook before connecting the cables up?

Try going to System Preferences>Displays and make sure you have Mirror turned on. Also, make sure that you have the powerbook plugged in to Video 1, you might need to go to video 2, or if you are using the S-Video cable, you might need to go to the S-Video setting. Hope it helps.

I did try to have both laptop and TV turned off before connecting cables and then turned both units on.. I have the S.video cable from that jack on TV's video 1 connection to the S.video option on the DVI adapter (I've also tried going just straight S.video to S.video) and the RCA audio on the TV's Video 1 connected to the laptop headphone jack. Audio on TV works as I play the download.. I did get the TV image to show a ? wacked out black and white version of what was showing on laptop.. like a split/swapped image .. right side of the laptop screen showing on left of TV and left of the laptop screen showing on right of TV. I tried checking setting on display on system preferences .. selected the mirror option .. something seems weird? never did see other than black and white.. and wacked out image on TV.. audio was fine.