What, exactly, is shorted, or are you using the term as a synonym for "dead?"

The only truly expensive cause of a dead compact's supply is a shorted flyback. The other high failure rate items are fairly cheap (things like bad solder joints, dead rectifiers, blown filter caps, open coupling cap, etc.) and easy to identify. So, unless you've determined that you have a bad flyback, it's definitely worth fixing. Even if the flyback is bad, you may still be able to find a cheap organ donor and get it back up and running.