Thanks for the guide. I would not have attempted this without your help.
After replacing the main board, the only issue I am having is that the top focus point is not lighting up when I select it. It still works as a focus point, but is not light in the view finder as red. I probably did not perfectly seat one of the ribbon cables. It would be nice if someone new which cable controlled lighting in red the focus dots in the viewfinder.
Thanks so much!