Wireless Network Issue With Pismo


I have a netgear wireless box attached to my cable modem and a G4 desktop connected to the router through ethernet. I also own a powerbook pismo and a dell laptop. Everything is working fine except that the pismo has stopped connecting to the wireless network (the dell is still fine). It has connected in the past. After checking that the airport card was properly seated and all the software settings I concluded that the airport card must have gone bad (it was dated 1999). I purchased a brand new original airport card on ebay and installed it, but the wireless connection is still not detected. I'm thinking that the antenna has gone bad - this is a pretty old powerbook. I saw a pismo antenna on sale on ebay. I'm hesitating to send the computer for professional repairs because the repairs will probably be more than the value of the computer and I don't want to give up the laptop for several days because I still use it.
Replacing an antenna is not a topic covered in any of my troubleshooting and repair books. I'm fairly good at replacing computer parts - I'm installed hard and optical drives, memory, cards, a processor on my desktop, and even a new keyboard on the pismo. I've taken desktops - but not laptops - apart. However, I'm not an apple repairman. The question is, is this a repair a fairly competent person could do and are there directions anywhere? I realize this will involve taking most of the insides of the computer out, which doesn't bother me, but I don't want to ruin my machine.
Welcome to MacOSX.
Not sure this is the problem. I have been reading that netgear/Linksys systems and Macs have encryption incompatibilities. Users are finding setting the encryption on the lowest setting has helped. Moreover, this link may help: http://www.macosx.com/forums/search.php?searchid=426564

Can you try the Prismo at another wirless spot (Eg., Starbucks, etc)?