My wash-hand mixing bowl plug does not work.? It is the kind that is to say attached to a rod...

It is the kind that is to say attached to a rod at the back and it appears to be the little screw attaching it to the rod will not tighten up which let the rod slide freely, any suggestions please.
Answers:    If the screw won't tighten because it's just turning and not gripping anything later the thread has stripped. If you can bring it out (try pulling and turning anticlockwise at the same time) you can replace beside a self tapping screw. Take the outmoded connector off both rods and transport it to a diy shop and look for the correct size self tapper. It's probably quite small but hopefully you'll find something. Ask them for facilitate.
Good luck David..
Replace it?