I've never done anything like this to my iBook but I keep thinking: as long as everything is connected correctly it should work fine right. Obviously I'm no Apple technician but your best bet would be to double-check everything you did.
This is of course assuming that the iBook was in working order when you got it and that there isn't any problem with the power supply [dead battery] or the connection. In this case then I would try and put things back as they were and see if that fixes things.
If none of this works then I would try and send it back to Apple; though I'm pretty sure that this mod would normally void your warranty, so simply just don't tell them ;).
Good luck,
Mark.