Macbook Air 2015 820-00165 S4_PWR_EN missing

[BakirIzmetbegovic]

Hello folks,
I got an MacBook Air Late 2015 for not charging battery.
Battery is good (400 cycles) and everything was working great but battery won't increase percentage. But will charge if connected to another MacBook.
So I wanted to make sure that battery connector J6950 was good so I added more solder to the connector pads. After that Laptop won't turn on at all.
But charger cable gives me orange light.
After that I noticed that I accidently shorted 3 small pads with solder bulb right next to the connector. those pads are from Q2090 numbers
3 = DBGLED_S3_D
2 = S4_PWR_EN and
1 = GND

and since then there is no voltage on pin number 2, I measured on a working board there should be 3V34 if I remember correctly.
I even injected 3V34 on that pin but it didn't helped. So rail S4_PWR_EN is missing.

Can anyone help me where to look for, what component went bad ?
And if I fix that, what should I look for the first problem not charging the battery ?

Thank you and regards.

[BakirIzmetbegovic]

Re: Macbook Air 2015 820-00165 S4_PWR_EN missing

Thank you all for the reply's and support. I appreciate the help.

[mon2]

Re: Macbook Air 2015 820-00165 S4_PWR_EN missing

Post clear pics of the actual pcb where you have soldered.

You will need flux and desolder braid to clean up excess solder / solder blobs off the pcb pads. The heat must be enough to suck up this solder and do so without tearing off the pcb pads.

Do watch videos on YouTube on the use of desolder braid to get a clear idea of the process.

[BakirIzmetbegovic]

Re: Macbook Air 2015 820-00165 S4_PWR_EN missing

I have cleaned those 3 pads as soon as I noticed what have I done. But it was too late, S4_PWR_EN was 0V after that

[reformatt]

Re: Macbook Air 2015 820-00165 S4_PWR_EN missing

PM_SLP_S5_L is what you are missing. Follow the power sequence here to establish why this isn't being generated:

https://logi.wiki/index.php/G3_to_S3..._and_Broadwell

Charging faults aren't usually anything to do with the battery connector. Usually it's a bad LIO board or flex, a bad charger, or the SMC. Battery connector needs to be floated into position with hot air underneath the board, not something you can do with an soldering iron really.

[BakirIzmetbegovic]

Re: Macbook Air 2015 820-00165 S4_PWR_EN missing

Customer did not want to wait for long so I used this board as a donor and fixed another board so at the end customer got a working Macbook. But I wanted to know what happened here and to know macbooks better so in the future I can fix them with more ease.