How much flexing and bending did you do to get the board out. I never remove those boards, I just free the top and fold them down enough to get at the back. Did you happen to completely remove the board?
My suspicion is that in the process of doing whatever changes your mod requires, you probably broke off one or more of the wires in one or more of the ribbon cables. That is the gray flat things between the socket board and the main board.