Q: Why doesn't my charger work anymore?

The chargers do not have a fuse.  The 13" MBP should have a 60 w Charger, the 15" Mbp should have an 85 w charger.  If the second charger was purchased from Apple, it may be under warranty.  If so, have it replaced.

Ciao.

Neither the AC input, nor the DC voltage is a problem.  The power adapter have several internal protective mechanisms, including an internal resettable fuse.  You haven't provided any details regarding the power adapter failure, so, here goes.  You should disconnect the power adapter, both from the computer and the wall.  Wait 15 seconds.  Using the 3-prong AC cable, plug the power adapter into a properly-grounded AC outlet.  Plug the Magsafe connector into the computer.

Your tip worked for me, thanks Carl.

see

http://support.apple.com/kb/HT2346