The Wrt54g Revival Guide in case you make a mistake of some kind..

ok, you INTENDED to upgrade or enhance your wrt54g, be a little CONSTRUCTIVE, but instead you were DESTRUCTIVE and you " bricked" it..
stuff happens. maybe the information here, both from linksys and some "unofficial" individuals, will get you back on the air. several things here to try in case you end up with a nice blue paperweight.. some are as simple as using a piece of wire run from your antenna to a certain pin on the circuit board, this will sometimes unlock a bricked up router. also several de-bricking programs. the site has some very nice pictures for assistance~ at this point, what do you have to lose? you cant break it more than broke~ good links too.
http://homepage.ntlworld.com/linksysinfo/revival/