Updated version of the 2015 Retina MacBook. Model A1534, EMC 2991.

53 Questions View all

Little yellow button on logic board - what is it?

MacBook Retina 12" Early 2016

My MacBook doesn‘t turn on after SMC reset. I've found on Apple pages that this can happen if you reset the SMC without your MacBook connected to its AC power adapter. I've also tried PRAM and SMC reset and nothing.

Black screen, no charging sound and battery picture when connecting to power supply.

I wonder what is this little yellow button on logic board for? Do any of you have a problem like me?

Does anybody know location of power on pads?

Block Image

Answer this question I have this problem too

Is this a good question?

Score 2
Add a comment

1 Answer

Most Helpful Answer

As far as I can work out, it de-energises the battery rails.

I'm also looking for the power on pads. and can't find them. They're listed in the servicer manual though, so should be somewhere...

Was this answer helpful?

Score 1


Correct, always press this button (hold if 2016 onwards model) and wait for the light next to the battery to go out before disconnecting the trackpad cable, otherwise you can kill the MacBook (trackpad deals with G3H always on rails).

If it is dead after an SMC reset, take it to Apple and they should sort it if it isn't too old. If they are not helping, press this button on the logic board, then plug the charger in. If it is still not working, there is an issue with the logic board most likely.


Also, you don't need to use the power pads. When this is de-energised, it will boot up by itself after the charger is plugged in


Have you solved the problem?


So, removing the trackpad cable will kill the mac, if I don't press that button first? This is nowhere in the disassembly guides. ARGH! Is there a fix? You mention taking it to Apple?


Add a comment

Add your answer

Wojciech Pawlowski will be eternally grateful.
View Statistics:

Past 24 Hours: 2

Past 7 Days: 35

Past 30 Days: 65

All Time: 733