New answers tagged magsafe
A good description can be found at Teardown and exploration of Apple's Magsafe connector Below is taken verbatim from the above link. The charger startup process When the Magsafe connector is plugged into a Mac, a lot more happens than you might expect. I believe the following steps take place: The charger provides a very low current (about 100 µA) 6 ...
Mixing answers from @David Anderson and @Brandon : The inner large pins are V+ (16.5 VDC). Measuring with no load will give 6.86 VDC; the full 16.5 V is provided to the proper load. The outer large pins are Ground. The tiny center pin is a Charge Control pin that assists with changing the LED color, and also assists with switching the adapter ...
Your charger is not the issue as evidenced by your testing it on other MacBook Airs I've tested the charger with multiple other MacBook Airs, and the charger works fine. You have a problem with either your logic board and/or your DC Power I/O Board. You need to take it in for service.
Not sure what is going on, but, I've found that even though the machine looks like it is shutdown, I have to hold the power-button for 10 secs for force turn it off. After I've done that it starts up fine.
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