I recently bought a '74 Univox Hi-Flyer bass. The previous owner had taken out the original pickups and replaced them with pickups from a Gretsch Electromatic.
He had wired them incorrectly, so i took it to a local shop. While i was there i asked if he might be able to use the original pickups instead.
So, he calls me a few days later and says that they're "dead", and just re-wired the existing pickups.
Now, i've played bass for a while, and i've never heard of pickups dying. They're just some passive humbuckers. Can they really die??!