MacBook won't power on from battery

There are 11mo of warranty left. I'd rather learn something new about these models than drop it off at the ARS.

And the power button works, because i can power it on with AC connected... I thought that was clear

@reverendalc strange. I assumed the power button was not working since this model will boot when there is no battery detected and the charger is plugged in. It sounds like the battery is fine if it is lighting the LED on the board when the power is disconnected. Have you removed the board to check for liquid damage, and checked the gold connectors on cables as well?

To diagnose it properly, you would need a variety of testing parts, which are expensive. You would also need to get the schematics for the board, and have the tools required for logic board repair, since it sounds logic board related if both the battery and keyboard are fine.

As @mayer said, it has a warranty so I would recommend dropping it off to Apple to see what they say.

i came here to learn and to fix, i'm well aware of the warranty status. i have the a1534 emc 2991 schematic, and a wide variety of electronics equipment from testing to reworking. i'm not particularly knowledgeable about low voltage electronics as my career experience is 120/240/480VAC, but i'm capable.

i'm not able to quickly decipher the schematics, but if somebody could point me in the right direction and give me a nudge, i'd appreciate it.

@reverendalc have you checked the board for liquid damage? It could be logic board related, but if there are no signs of liquid on the board, it is likely a plug in part.

It's a strange issue, but I would say either take it to Apple or a 3rd party repair centre, who has a test battery, keyboard, etc. You don't want to drive yourself crazy measuring power rails and checking for signals on the logic board, if it is not a logic board issue. I understand you want to learn, and if the parts are cheap, I would say go for it. But since people are charging £15 for the keyboard cable, £20 for the trackpad cable, £60 for the keyboard, and £120 for the battery, I would suggest just taking it somewhere who has the part available, since it could be an issue with the battery PCB for example.

If you do insist, and have a schematic as well, check the signal SMC_RESET_L and SMC_ONOFF_L (names will probably be different on your model, just look for a similar signal around where the trackpad cable plugs into the board) and see if there is a difference in voltage drop between pressing the keyboard when it is off and when it is switched on. If there is, it could indicate a keyboard issue where it is not dropping the voltage enough unless it is in an on state, but again, you would need to test it with one to check.

Personally, save the hassle and take it to someone. If you really want to get into this field, do what most people do and buy a cheap 2008/2009 faulty MacBook Pro from eBay, and check that out :)

i currently have two 2016 MacBook 12" models, gold and gray. the gold is behaving abnormally, and the gray is working properly.

what i have done is swap the MLB from gold to gray, which means all new everything from a known working machine. the result is the same.

to elaborate, even when on wall power, i have to press the power button multiple times for various lengths of time before it powers on, but once it's on, everything is as normal. i can safely remove the wall power, and the mac will remain powered on from battery. OS X reports the battery is connected, charging, and normal condition.

i can't stress enough, this isn't about money, this isn't about preservation of warranty, this is about me coming to a repair support community asking for support repairing something. i know many of you are for more experienced than I with component level repair, and i hope to tap that knowledge.

It is a strange one. So you isolated it to the board. At this point you have to google for schematics and start following the charging circuit.

I've never had this same exact case, but I would troubleshoot charging and SMC first.

i am currently looking at a 2015 mb12 schematic, and am polling voltages along the PPVBAT_G3H line. unfortunately i cannot get the board view to open, and i'm not sure how similar (or dissimilar) the 2015 and 2016 MLBs are.

You have an invaluable "joker" which is the working MacBook to compare voltages, resistance, diode mode readings!

I am not sure about how they compare as well, but I was before able to fix a board without having the exact schematics by "reading the board." And by comparing similar circuits. As is board lay-out may be different, but the science is fundamentally the same. So you'll find the same backlight circuit, Thunderbolt controller, sound controller, charging circuit, etc. although they may be laid out differently if not very similarly.

i have procured the 2016 schematic and board view. off to the races i go! i'll report back with my findings