MacBook Pro starts when plugged in. with battery/without battery also

Seems like the common case of dead battery syndrome. When you get to your desktop, go to the apple logo in the top left, about this mac, system report find power on the left side and take a screenshot of what it says and post it here. If it says that condition is not normal, says theres no battery or if the cycle count is over around 600 your battery is shot and you need a new one. Do all of this ofcourse with the battery plugged in.

Hope this helps and good luck fixing!

on the left side of your mac you have a button with 7 lights, if you push the button, are all the lights going on or is there just one blinking?

if there are more lights blinking the battery is working, in that case it's most likely there is something with the keyboard.

it is possible that the keyboard cable isn't connected properly or damaged. or that your keyboard has fluid damage.

I got the same problem. I have try reset SMC & PRAM, remove battery & RAM, reinstall MacOS High Sierra z which all does not work.

My battery condition show Normal & actually i just change the new battery two months ago only so it's new & does not charge many cycle.

I suspect might be because install some software & crush the system in MacOS high Sierra.

As after i upgrade the MacOS High Sierra, it's working normal but after I upgrade the software due to compatible problem. It start to have this problem. I had tried to uninstall some program but still some did not do it yet as I need to finish some project on it & I afraid can't get back the software later so did not try yet. After I finish the project, will back up the data & try to uninstall all the upgrade software.

Might be you can try if you got the similar situation or if you have already solved your problem, kindly keep me update.

I will update the result after I uninstall all the software too.

Let's keep in touch !

I took my mbp to the icare and they removed the dead battery and then i start having this problem … my mbp 2011 start by itslef when plugged in .

@yarangula URALI

Not sure if you ever solved this issue, but I am having 99% the same issue you are having.

The computer only turns on after I have unplugged the battery, and auto turns on after plugging in the mag safe power cord to the computer. The computer turns on without even pressing the power button.

This particular computer might have experienced some water damage as I had to replace the logic board to get it to even display a picture on the screen.

One way you could test to see if you have a faulty power button is to boot the computer, and see if you can force shut down the computer holding the power button down.

This is something I just tested, and just noticed I can not turn off the computer holding down the power button, so I am assuming there is something faulty happening with the power button.

I have the same problem, Macbook Pro 13* 2012, after break plastic coating (blue one on mbp 13” 2012) on MagSafe Port. Did you have that that cause too? If yes, maybe the problem is that the paper/sticker coated.

I chatted with an Apple Advisor and she told me to reset system power management on the computer. I have a MacBook Pro early 2011. The steps are mentioned below. It didn’t work the first time so I tried twice. After the steps were completed, my MBP is not starting automatically when I connect the charger. I have to press the power button to start the computer (and that is how it should be).

(A) On the Mac, press and hold the power button for 10 seconds and wait 30 seconds before proceeding with the next steps

(B) 1. On your built-in keyboard, press and hold all of these keys:

• Shift  on the left side of your keyboard

• Control  on the left side of your keyboard

• Option (Alt)  on the left side of your keyboard

2. While holding all three keys, press and hold the power button as well. 

3. Keep holding all four keys for 10 seconds.

4. Release all keys, then press the power button to turn on your Mac.

(C) Once the computer is on, remove the charger, shut down your laptop. Then connect the charger. Hopefully, if you followed the steps, your issue will be resolved.

This solution works for me! I tried it many times (at least with three batteries). Every time I changed the battery, the problem appears: autostart when plugged in. Now, after I changed the battery I need to run this command on the terminal!

$ sudo nvram SystemAudioVolume=%80

Actually, the command is to disable startup sound, but it works too to prevent autostart when plugged in. Probably, the actual solution is to reset nvram, as I did in the comment above.

I had the same problem and for me, it worked like this:

press together <ctrl><alt><cmd> and the <power button> for a few seconds, and then it turns on without the power plug.

Didn’t work for me but thanks anyway. My battery was charging after installing the first time but since I wanted to calibrate the battery I let it get completely empty and ever since it’s not recognizing the battery anymore so I have to keep it plugged in all the time. No worries though, not using Apple anymore with all of their surveillance.