Shure will fix it but not for free. Contact them and see what it would cost. Might be as cheap to buy another one. Not sure. I had them redo one of mine once and I think it was $45 at the time. I inherited a broken one just like you.
usually, the only thing that breaks in those, is the wires inside become disconnected. Just unscrew the mic head, and see if the wires have become disconnected from the head. If they have, resolder them, and have fun, or something else is wrong.
Well, they last a long time but not forever. The capsule itself will eventually deteriorate in performance from fatigje, climate & spit rot. From my experience, average life around 25 to 30 years before they start sounding kinda crappy but could be less or more depending on useage & conditions. Sure does still have the replacement policy. A buddy of mine just had a 58 replaced about a year ago & I think that was somewhere between 50 & 60 bucks at that time.
Just contact Shure for details.