i’m not sure if you read my blog entry http://abbyandwin.net/blog/2009/02/23/upgrading-my-imac-mb324lla/ but i’ve included 2 other youtube videos there that helped me while i was opening my iMac.
from your description, it sounds like you iMac’s airport card may have been altered/damaged. does your iMac still recognize that there’s an airport card installed? i’m not sure where the airport card is though. hope that helps a little.

win

I saw your video instruction on how to open an intel imac aluminium,
thanks very much, it helped me a lot, so now I have 1 terabyte to work with…
and it wasn’t hard at all, althoug my lcd had one black cable in the left side and 4 connections in the right side, so maybe I have different version than yours (that only had cable in the right side)

but maybe you can help: after putting it together again, and installing osx,
airport cannot find the airport base station (which works fine)
… is it possible that something happende during harddisk replacement,
do you know where airport is located in the imac?

but thanks again for your great video

regards
john