I recently bought a new power adapter off Amazon, and it worked with my mid-2014 MBP at work and my colleague's mid-2014 MBP, but not my mid-2012 MBP Retina 15" (which, frustratingly, it was bought as a replacement for). The green light comes on, but doesn't switch to orange to indicate charging, nor does the machine detect it.

It's literally the exact same model number of the adapter that came with my machine. I figured the replacement was possibly defective, so returned it and got a replacement. Alas, it still doesn't work on my mid-2012 MBP, but does work on my partner's mid-2014 MBP.

I've tried resetting SMC, to no avail. Even more confusing, my work power adapter charges my mid-2012 MBP fine, and is what I'm using at the moment.

Any ideas?

Edit: As requested, here are some photos of the sides of the new adapter. Side 1 Side 2

1 Answer 1


You have the wrong power adapter.

The Mid 2014 uses a 60W adapter and the Mid 2012 uses an 85W.

enter image description here

See this page Find the right power adapter and cord for your Mac notebook on Apples's website for details

You can always use a power adapter with a higher power rating on a machine that requires less, but you can't use an adapter with a lower power rating on a machine that requires more. In other words a MBP with a 60W power requirement will work fine with an 85W adapter, but a MBP with an 85W power requirement will not work with a 60W power adapter.

This is the product you want.

  • Thanks for responding! Alas, that is not it — my replacement adapter is definitely 85W. Again, exact same model number as the adapter that originally came with my MBP. Also, all the devices mentioned above are 15", so all use the 85W adapter regardless of model year.
    – aendra
    Commented Mar 1, 2016 at 21:23
  • If your work adapter is powering your MBP but the new adapter isn't, the problem is with the adapter. Long before your SMC and NVRAM come into play, your power board will communicate with the adapter, not the MBP (there's a chip in the mag safe plug). It "identifies" its power rating to your machine. Wrong power rating and it won't charge. Take a picture of the label on the side of the adapter.
    – Allan
    Commented Mar 1, 2016 at 21:30
  • Why then does it work with literally every machine that I plug it into — except mine? Like, I'd love for you to be right, but I've already had to fight with the seller to send a replacement, I don't think he'd send me another.
    – aendra
    Commented Mar 1, 2016 at 21:38
  • Though, you might be right — have just tried both a SMC and PRAM reset regardless, still not working. Further, I've noticed it emits a high-pitched whine, there's a chance that it's a counterfit adapter... At any rate, have added more details above.
    – aendra
    Commented Mar 1, 2016 at 21:47
  • 1
    Take a look at this video I found on YouTube. youtube.com/watch?v=mxoQMhfu4k0 I noticed that your power adapter is made by Liteon where it should be Delta. I think you have a counterfeit adapter.
    – Allan
    Commented Mar 1, 2016 at 22:16

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .