Hold up a minute there pardner. I've never been inside a 190 myself, but often the board that the power plugs into is a separate board from the actual main logic board, called the DC Board or Power Board or suchlike. See if you can find the service manual for that model before you give up, and try ifixit.com and welovemacs.com to see if either have take-apart guides for that model. That should tell you which actual board you're looking to replace.

Apart from that, do as the sig says, and don't muck about with power supplies again, mkay?