Replace built in airport card

Hi I just bought my first mac and its a used iBook G4. I believe its the model no. M9846LL/A 1.33, 12-Inch, 512 MB of built in RAM,40 GB Hard drive. Is there a website that tells you the actual model by just typing in the serial no.? I would like to know so I can buy the right memory and hard drive for it. Anyway, The airport card is broken and the guy who sold it to me told me that the airport is built in (soldered) and I cant replace it. I there a way to replace a built in airport card? like buy a functional one and have a technician replace the broken one.

The airport cards in iBooks are under the keyboard with the memory slot. There are 2 little square spring-loaded tabs at the top of the keyboard. Pull these toward you with your fingernails and lift the keyboard at the same time and it will lift up. Be careful as there is a ribbon cable attached, but there is room to carefully lift the keyboard up and pivot it over to get it out of the way. Then you can see the airport card which slides in sideways into a slot, and underneath that is the single memory slot. It slides into a slot and is not soldered, but be careful when removing it as the antenna cable plugs into the end of the card and you have to remove it before pulling it out all the way. Maybe the airport card just came unseated?

http://docs.info.apple.com/article.html?artnum=58535

BTW its just PC-2700 DDR SODIMM (notebook) RAM. Add a 1GB stick and you will have 1.5GB of ram. The harrd drive is just an Ultra ATA/100 style in the 2.5" variety. Dont get the new SATA or PATA styles as they won't work (different connectors and different technology)

thanks. I looked under the keyboard and there is no airport card. The ram cover is flat unlike the ones i seen in ifixit where there is a space for the airport card and an antenna plug in under. I will post a picture later