sound card problem

hey guys

so i installed the leopard.. all is ok except one thing and the most important, please try help me..

the sound card is working, i can hear the sound thru the build-in speakers of the laptop, BUT -- when i put the cable into it (to the headphones hole) i still hear from the speakers of the laptop and it's not taking the sound out to the headphones. it's like there's no reaction when i put the cable.

what do u think it is?
and also i wanna know how can i reinstall the driver of the soundcard.
when i go to "System Prefereces -> Sound" i found in the device only "HD Audio Output" under the tab of "Sound Effect" and "Output", and under "Input" tab there's nothing, empty.

what do u think guys?
i really need help (i really tried to image u it from here)
peace!! help

Zap the PRAM, it will more than likely fix it.

how can i do it?
i mean i am very new on leopard..

i can do it manually without keyboard-shortcuts?
(i don't have apple keyboard..)

someone???

No you need to use shortcuts, go to the Apple support page, it probably has the alternative keys on a PC keyboard setup for you, just do exactly as the procedure tells you.