Mid 2009 Model A1278 / 2.26 or 2.53 GHz Core 2 Duo processor EMC 2326

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Repair/convert Magsafe to Magsafe 2 with new DC in Board?

I have a MacBook Pro 13" unibody mid 2009 model A1278. I have two non-functioning 60W power supplies that had the MagSafe "T" type connectors that have failed (and have since been cut off). Both units are labeled with output of 16.5v=3.65A I have tested both units using the same 3-prong wall-to-power-brick cord by testing on the two bare wires (the inner white jacketed and the braided shield).

The first is the original Apple one that came with my laptop. It tests at 6.67 DC volts out which seems close enough according to other posts on Q and A forums here.

The second unit is a 3rd party vendor (unknown) marked only as "replacement AC Adapter" and "Model No. S165365." (Which seems to be a common thing according to my searches.) It tests at 16.83 DC volts out.

Also, my DC in Board connectors are fried.

I would like to repair the two MagSafe power cords by buying just the replacement cords but I do have to replace the DC in board.

So, my questions are:

1) is the Apple power brick output of 6.67 DC O.K.?

2) is the off-brand power brick output of 16.83 DC O.K.? (I am guessing so because it seems to approach that of an 85W? and I understand the MacBook Pro will adjust the draw accordingly?)

3) is there any advantage of the newer "L" type over the "T" type that I originally had or is it just personal preference?

4) since there is a MagSafe to MagSafe 2 converter (cord) available, can I convert the DC in Board to MagSafe 2 and repair the MagSafe power brick connector cords to MagSafe 2?

5) if so, is there any reason/advantage in doing so? Or should I just stay with older style MagSafe? (Is the only thing different in the MagSafe 2 is that it is thinner to fit into the newer models?)

Yes I know I can buy new complete power adapters pretty cheap but that is what I did to get the second one and it died pretty fast. AND, I have very limited funds right now but am very capable of the repairs (planning on just splicing the new wires the the old ones and not popping the bricks open.)

Lastly, have used your website a LOT! for this research as well as having already replaced the battery in this unit and an older MacBook about 6-7 years ago. So thank you for the help already and in advance for any additional help on this project.

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First Apple doesn't offer replacement MagSafe cords. Anything you find are used cords that someone cut off a dead charger.

So that leaves the question on how you plan to spice the cord onto the adapter. You could cut the case and swap out the cord that way or splicing it in-line. I don't like either method as both leaves things in a weaker state than a factory unit. You see the case can't really be re-glued reliably so you put your self at risk from the high voltages and the risk of fire. Altering the cord with a splice puts your system at risk if you misfire or if the line shorts out.

So fixing the MagSafe charger is a no-go in my book as you are more likely going to damage something which would be more expensive!

As to the cheap knockoffs: People and systems are been hurt by them. A few people burnt and a few fires started, I had heard someone was killed but I never was able to verify that. Which is why the cord was cut off as they can't legally sell the MagSafe units in a working state.

Now lets look at your real problem here. Are you sure the MageSafe unit is bad? what is the MagSafe LED showing you when you plug it in?

Here's some reference material:

Here's some peoples thoughts on the knockoffs: https://forums.macrumors.com/threads/wha...

Lastly you can't swap out the older MagSafe DC-In board to the newer MagSafe2 version the parts are not interchangeable.

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Dan, thanks for your answer and input. The link about the knockoffs was most helpful as I think it explains the higher DC out.

I believe the Apple MagSafe unit is good as it tests fairly close to the DC out but am still researching. Not sure about the knockoff one though because of the higher DC out. I'm fairly sure the cords are good because I am getting the readings.

There are after market replacement cords that come with the grommet and all but, as you pointed out, they are designed so that you have to crack open the brick, de-solder the old cord from the board, solder on the new wires and then try to reseal the brick.

I was going to splice the new cords in-line to the existing cord because of exactly what you said about trying to reseal the brick. Although I am sure I could, I would just rather not mess with the brick.

With a bit of solder, some heat-shrink tubing and a little skill, it should be fairly easy to splice the two wires in-line.

Just need to be sure about the DC outputs.

Thx again!


@karl1201 - There is three wires here + - and signal. You run the risk of shorting out the signal line if you're not careful. If you do you'll zap the sense logic which is on the logic board. I've had to tell quite a few people their systems where to far gone to repair due to damaged cords, home cord repairs (like what you are thinking of here) and due to bad chargers (knockoffs).

Find a friend who has the right charger to charge your system until you can get a real unit.

Don't be 'Pennywise, Pound Foolish' here its not worth it!


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Karl A will be eternally grateful.
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