You will need to change the connector on the circuit board, too. Just changing half of the connection is not good enough.

I doubt you have a short- IJ and others of that era had connectors that were undersized for the lighting load they were asked to carry. You can lighten the load by installing LEDs in place of the incandescent bulbs.

Read Terry B’s posts on desoldering. If you don’t have a good way to remove the solder, ie, a Pace or Hacko desoldering station, you would likely be better off to send the board out for repair while you repair the connector. There’s several folks out there that do board work- Chris Hibler comes to mind. He’s easy to find around here.