If none of the four controller slots are being recognised, it means your controller port is dead, as all four slots are a single piece. Its a common thing I've come across when I pick up used

s. For what its worth, its easier just to pick up a good

, otherwise you need to take apart your

and swap out the bad controller port with a good one. You can pick up the spare part usually for about $5 or so from stores that sell spare parts. If you swap it out, make sure the replacement has the same size pin plug as yours, as the controller ports have different size pin plugs on the inside.
My friend, ProtonX might have a spare

controller port as he repairs game systems for game stores.