iPhone XS Max手机经常重启，有的时候会无限重启

First of all, thank you very much for your patience!

Yes, you guessed it right, my battery level was inaccurate.

However, I also tried to replace the whole battery before, but the problem still exists, so I think it should be ruled out because of the battery?

But at present, I have no alternative to solve my problem.

Thanks a lot for your answer.

In your reply I see that you indicate that there may be some issues with the battery's connector or around the connector.

If I understand it as the circuit board of the battery or some components around the circuit board, then I took it to the maintenance master to check the circuit board, but the maintenance master told me that there was no problem with the circuit board.

The suggestion of the maintenance master, let me try to replace the chip.

Because my mobile phone restarts irregularly, the only regular time is when charging at night, when I wake up in the morning, when I check the analysis log, the phone restarts many times, and the interval is about 1-2 times every few minutes. .

When I unplug my phone from the charger, it restarts erratically. Sometimes it restarts continuously, sometimes it takes 5-6 hours to restart.

My interpretation here is that I'm thinking there's a problem with the I2C bus used for communicating with the battery.

I pulled some schematics of the iPhone XS Max, and the BMS communicates over I2C0_SMC. That signal goes to a chip labelled USB-PD and another one labelled Yangtze Charger. It looks like there's a level shifter circuit right next to the battery and of course caps and resistors in the line.

Although I have reference designators for those components, I don't have a board file that shows me where they're physically located, at least not yet.

However, the other thing of interest is that those signals appear to go through the interposer, meaning they're transferring from the top board to the bottom board (or vice versa). So in addition to the possibility of a missing or damaged component, there's also the chance that the interposer has flexed and broken some pads. That, of course, will take expert-level microsoldering repair, unfortunately if that's the problem.

@dadibrokeit That sounds very much like I would expect. I can look up locations if need be. But the XS Max board is extra weird. There is a small section of the board around the SIM tray that goes to only one level of board and then another small section at the bottom that's sandwich board again. I feel like all the charging components are in that segment.

@ownstupid I would definitely be looking into Yangtze if that wasn't the chip that was already recommended to replace (assuming you replaced it).