The MagSafe connector consists of a magnet inside the computer and an attraction plate in the DC plug on the power adapter. Since the power port has a magnet built in, whenever you service the system it is recommended to put a piece of tape over the connector to avoid materials such as screws and washers from being inadvertently drawn into it.
The DC plug consists of five pins. Each pin is spring loaded. The center pin is a sense pin (2). This center pin must make contact with the computer before power is applied. Power is carried on the remaining four pins (4). The outer pins are positive terminals, the inner pair are the return paths.
Since there is no up side to the DC plug, it can go either way. To support this design, the power LED (1) is on both sides of the connector. As always, the LED will glow amber when charging the battery, and green when supplying power to the system but not charging the battery.
Was this article helpful?