Whatever the cause may be in most cases it s actually the adapter and not the magsafe connector.
Mac magsafe power adapter not charging.
Disconnect the magsafe adapter from the mac and from the power outlet.
Maybe the adapter is not getting its power could be a loose socket or an improper connection.
It could be frayed broken or burned.
If your macbook pro battery isn t charging the most likely place to check for trouble is in the magsafe charging cable.
Let it sit unplugged from anything for about 5 minutes.
If you need help using your magsafe adapter see apple portables.
The macbook air comes with a 45w magsafe power adapter and the 13 inch macbook from 2006 2009 and t the macbook air comes with a 45w magsafe power adapter and the 13 inch macbook from 2006 2009 and the 13 inch macbook pro use the 60w power adapter.
The led on the adapter connector doesn t light up when attached to the computer.
A simple way to see if it s the problem is by doing a thorough inspection of the entire cable.
But it should power and charge your mac like the adapter that originally came with your computer.
If the 2012 macbook pro is the model without the retina display with the cd dvd drive then the 60w would work on both.
If connecting a magsafe adapter to a macbook doesn t light up the power led chances are the socket you are connecting to is not working okay.
Inspect every inch of the cable.
The adapter s white insulation separates from the magnetic end of the magsafe connector.
The adapter only charges the computer intermittently.