MacBook Air A1466 (820-00165) charging problem.
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- Опубликовано: 7 сен 2024
- This machine was water damaged and the battery management system "BMS" which is located inside the battery shorted causing damage to the SMC data lines that communicate with it. The system management controller "SMC" integrated circuit because of this damage was unable to properly over come a 2k Ohm pull up resistor to properly pull down the data line and create data signals to communicate with the BMS and U7100. These packets were visible but were not properly pulled to ground. The SMC was fully functional otherwise and the machine did power on and operate.
I go into detail of the charging circuit and how it works. Covering not only the communication between the SMC, BMS and U7100 and show how these should look on an oscilloscope.
This is the first time I have seen this fault. I did save the defective SMC and may make future videos with this part.
This machine helped me dive into a area of the board I have not had to troubleshoot in great detail and gave me a much better understanding of these systems and how they work. This was not the kind of repair where you could see damage on the board and just fix it. You had to read the schematics and figure your way through the system. The SMC chip is not something you change to "just see" if it fixes your problem. It is a last resort and you want to prove it is defective through troubleshooting first.
I enjoy challenging faults that force me to expand my knowledge of these boards. This was one of those repairs. These circuits and communication data lines are basically the same on all MacBooks regardless of model so hopefully this can help you in the future.
Amazing, thank you for a very informative video,
Quick question, my problem is not recognize the battery at all.
that was awesome explanation
Super cool explained
great explanation of the charging circuit. But are you measuring on a normal working board or does it still has issues? I'm confused with the extra rolling text at the end?
My MBP works OK but battery is not recognised, I'm not sure if it is the BMS or the charge circuit. Cell voltage is 12V combined. On scope I can see similar like yours on SMBUS_SMC_5_G3_SCL and _SDA, so I suspect BMS. But what exactly in the charge circuits decides that the battery is OK? Can I measure this somewhere, to be sure it is the BMS that is bad?
same issue, did you find a solution ?
D6950 says “no stuff” and is not populated on the board. Great explanation though.
I have macbook air..charging problem..no indicate charging in the screen but has a orange light..and battery is full..what is the problem ???
What program do you use to view the boardview
Sir, I have the same exact problem with your mac air a1466 with water damage and won’t charge the battery. The resistor close to SMC chip that you pointed with the pencil has a broken trace and I make jumper to it. I also changed the Q7155 but the problem still the same. What is the real culprit in this case sir ? TIA🙏
If it sees the battery and it's not charging it, it's the black SMD resistor with the inscription 4R7, that's right behind the wifi card, there is another resistor with the inscription 100 next to it, cheers!
Please I have the same problem, but on your video we didn't see the solution, what components did you replace?
Mine doesn't recognize the battery
Hello, I know this question has been asked before but I'm using board-view and it's a little clumsy, don't get me wrong its a free programme and I would not of do so well without it, but would like to upgrade to what you are using to track faults, please could you tell me which schematic software you're using in this great video, all the best.
pldaniels
Charging not increased how to solution
link program viem bro?