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Repair information and guides for the updated version of the 2015 Retina MacBook that was released in early 2016. Model A1534 / EMC 2991

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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?

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Pressing this button brought my MacBook back to life. It had died during attempted update to Catalina 10.15.6 and was completely unresponsive. After pressing the button 3 times 10 seconds each, and then powering up, the install completed successfully and the computer works fine.

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Old Post, but commenting for prosperity.

EXTREMELY IMPORTANT

For this model MacBook it is IMPERATIVE that the battery disconnect button be held for 10s (until the tiny led dies) before removing the track pad flex, else you can kill the logic board.

On power back up post repair it is IMPERATIVE that the MacBook be connected to a standard USB charger (5v 0.5-1a) until it powers on before connecting to the standard MacBook charger. This is to wake up the power management circuit. Connecting directly to a standard charger after having disconnected the battery can likewise permanently damage the logic board.

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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...

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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.

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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

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Have you solved the problem?

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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?

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How i can energise the battery rails again? i have pressed this button and macbook doesn't power on.

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I did the same thing: I initiated a restart, then held down the “shift, control, option” keys and hit the power button without plugging it into . My MacBook never started back up, same as the above post.

I followed the plan that the original post: opened the computer and pressed the small button adjacent to the internal lcd power light with the computer plugged in to the wall outlet. The charging alert rang and I knew my computer was back to life.

Do follow the disassembly instructions on ifixit when you are removing the screws and removing the bottom casing. The flex cables are very delicate.

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