George, not sure if you already bought a new one, but these are pretty easy to fix.

1. snip the rubber end off the cord, then strip the shielding back on the wire.
2.If you choose to try to re-fit it, hollow-out the rubber end you snipped off, and slide it down the snipped wire so it can be slid back up to cover the tip once the repair is done. If you are like me, toss the rubber end and just wrap the end in electrical tape once it's repaired.
3. expose enough of the wire mesh around the core (just under the sheilding) so you can wind a small pigtail that is long enough to solder. This is your ground. You will also have had to strip back enough of the wire to expose the copper wire at the core (enough to solder).
4. Solder the copper core wire to the center tab on the back of metal tip. Solder the mesh pigtail to the tab that connects to the barrel portion of the metal tip. Make sure you have some type of shield between the two new solder joints to keep them from touching. shrink tubing works nicely...if you slipped it on prior to soldering. Can use electrical tape as well.



I repair laptops as a side business and most of the power supplies I use on my test bench were repaired this way after someone else cast them off as broken.