Power Book G4 harddrive help.

[terrormiah]

Hey,
I'm a newb when it comes to macs but, a while ago my friend gave me her old powerbook g4 saying that the harddrive was fried. Well I just picked up a new hitachi harddrive and harddrive ribbon. (i threw out the original by mistake) I plugged it all in to the logic board but the harddrive won't show up in the os x or 9 installation. I ran the hardware diagnostics and it came back with no errors. I've gotten a removable disk to work on it before but after I've installed it still wont boot. please help