You may have just disturbed a connector when putting the wiring back into the bottom bracket controller holder.Quite possibly, I didn't actually get the board in at all till I realised there was a groove, but as I say it is possible.
Is there a way I could know for sure if I had?
I was thinking I had loosened a wire or something because it was a tough job getting them all back in place.
I think you should carefully pull it all back out again, check security of the connectors and also check if any of the connector pins have backed out of their socket.
I remember those days of trying to stuff all the wiring back in, and I feel your pain lol