iBook G4 Airport

I have an iBook G4 that I use for light internet browsing and DVDs however, I switched it on this afternoon to discover that the Mac was saying I hadn't got an Airport card installed. I ran the Apple Hardware Test and it told me there were no faults and that Airport was working fine. I booted into OSX 10.3.3 and when I tried to connect to WiFi, there was still no Airport card installed. I need help in solving this. I have tried Option, Command, P,R and it didn't work. Thanks.

iBook G4 14 inch, 1.07 GHz, 1GB DDR SDRAM