Hi everyone got the strangest problem ever!, port 1 is not recognising an official controller but works with an 8bit do wireless controller. The controllers work fine in port 2 and on my other saturn. So the port and logic seem ok, but what could the difference be between an official pad and the 8bitdo? Took a quick video to show you.
I'd clean the connectors for a start, then do a continuity check on the controller cable, then the filter parts on the console motherboard, see if all the signals can correctly reach from the controller board to the SMPC.