Fix Your Stuff Community Store

AC power adapter for MacBook, MacBook Pro, and MacBook Air. Uses a self-aligning magnetic connector that disconnects safely when tugged. First-generation (2006-2012) MagSafe chargers have a slightly thicker, L-shaped connector. Available in 45 W, 60 W, and 85 W versions.

65 Questions View all

Options

Magsafe adapter doesn't work. What should I check?

Hi.

My Magsafe 1 AC adapter (from Macbook Air, 45W) doesn't work suddenly. No LED indication what so ever. No damaged visually find, even wire is fine.

I have a volt-meter, so I can check some resists or volt. Please let me know what should I check...

These are current status :

Pin 1+2 : Not shorted. 0.44V, 200k Ohm when not plugged in, 5M Ohm when plugged in.

Pin 4+5 : Not shorted. 0.44V, 130k Ohm when not plugged in, 2M Ohm when plugged in.

Pin 1+5 or 2+4 : Shorted, 0.0V, 0 Ohm

What I heard, it should about 6V when it's not connected to notebook. Mine does 0.4V only.

Help me please.

Answered! View the answer I have this problem too

Is this a good question?

Yes No
Score 1
1 Comment

Standby output of Apple's MagSafe Power Adapters varies between models. Yes it is often said to be "6V", but that is "old knowledge" which pre-dates 45W and MagSafe 2 models. (I'll share two standby potentials which I measure: Model A1424 is around 3,15 V; Model A1435 is around 0,6 V.)

Unfortunately, I am not able to help you with your misbehaving unit. I hope this little bit of knowledge will be useful to anyone, whom suspects their unit is faulty just because its output potential is not 6 volt.

by

Add a comment

1 Answer

Filter by:
Most Helpful Newest Oldest
Chosen Solution

Options

Here a picture (on the right) or the pin outs: http://en.wikipedia.org/wiki/MagSafe

Pin 1 0 V

Pin 2 V+ @ 14.5 / 16.5 / 18.5 / 20 V DC

Pin 3 Charge control pin

Pin 4 V+ @ 14.5 / 16.5 / 18.5 / 20 V DC

Pin 5 0 V

Was this answer helpful?

Yes No
Score 1

4 Comments:

I do know that. But currently pin 2 and 4 only out 0.44V which supposed to out 6.8V with regular reference like Wiki.

BTW, I checked well working adapter too and it also out 0.44V. I don't know what to do next.

by

I tried to reuse a 45w MagSafe adapter for hobby purposes and I'm also getting 0.44v on the power line and 200k Ohm resistance. I tried to put a 39.41k load on it to make it start delivering power (works on other Mac power supply) and it didn't want to start. It would be helpful if anyone knows how to bootstrap this power adapter.

Thank you!

by

Had the same problem.

I found on few solutions to heat up the power adaptor, first I thought it's stupid....

But as described above, had only that 0,44V on power line, after about 15 minutes of sitting on power adapter suddenly the MacBook Air (mid2011) switched on by it self !

Don't know what might be the reason for it.

by

Sylwester - It's best to replace the charger with a new one. Heating it won't really fix it only postpone the inevitable.

by

Add a comment

Add your answer

Anonymous will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 5

All Time: 2,077