Andrea, a pbulb has gone bad when it dessicates to almost nothing. it will turn may be a dried out brown color. As long as its still green, its still doing some good unless it really is just completely deflated. However, if the plant hasn't been divided in a good number of years, then it would behoove you to cut away a fair chunk of the old leafless pbulbs (read: follow standard dividing procedure).

I think that you had been watering it insufficiently or the root had rotted from too much water. You can repot it in a bark mix with some sponge rock and charcoal. After repotting, soak the pot in a bucket of water; maybe for 12 hours. This can rehydrate the roots and after a week, the âÂÂpseudobulbsâ should return to normal.

Can you actually rehydrate a PB once it has wrinkled?