Powerbook g4 (al) s-video not working

[finlaymurray123]

I am fixing my uncles pbook g4 and it has a dvi and s-vid port (dvi smashed up) and i would like to connect an external monitor in single user mode as the screen is smashed and he doesnt know his own password. Note: the s-video cable to (the yellow, white and red cables- component avi right?) works on a pc, but even on the login screen of the mac it doesnt work -i try pressing f7 and nothing happens. Is there some key cobination to get it to work -like say cmd+shift+D or something but the main thing is i need it in single user mode as i can only see the top left corner of the screen. PS I can't erase the os because i need to recover his data