iPhobe XS wont charge after battery replacement

[AJ847.63e]

Hi All,

Replaced a original XS battery yesterday as it was down to 78% battery health and would drain from 100% to flat within a day or so. After replacing the battery we noticed the battery would not charge, ie the phones not coming up with the charging symbol. I tried connecting it to 3U tools and that is unable to detect the phone. I took the phone apart again and this time removed the screw plate covering the connectors and left the display hinged open to make sure nothings shorting but no change. I then found the vol +/- and vibrate ribbon connector on the ribbon side has a few bent pins, could that cause a charging issue? The buttons are not working either when the phones on so that clearly needs to be replaced.

I disconnected the battery and hooked up my USB C meter and the phone initially draws 5V 0.0090A than jumps up to 0.0135A than dips back down to 0.0090A and continues fluctuating around those areas. I took resistance and diode measurements of the battery connector but unfortunately haven't been able to find reference XS values and I don't have a ZXW license. Values are (measurements taken as battery below connector and ground pins excluded) :
Pin 1 Bottom left R=3.5 D=0.001
pin 2 R=3.7 D=0.001
pin 3 R=3.6 D=0.003
Pin 4 Top left R=1 D=0.002
Pin 5 R=1M+ D=0.415
Pin 6 R=1M+ D=0.415

I'm thinking Tigris is bad, but wanted to get some advise before I go gunho on the usual suspects. Seeing pins 1-4 seem to have shorts I have not tried a new dock connector, plus I also do not have one to try. I noticed there are multiple versions of tigris and tristar, is there a way to find out which one your board uses without taking the board apart? I do not have a board separator so I would have to order one.

Short bit of history, about a year ago I replaced the display as the phone was dropped and the display had the typical green line in it. Replaced it with a OEM refurb as I do not trust aftermarket displays. Wondering if this has something to do with the battery dying so fast. The phones only a year and a half old, and it's barely used. That's really quick for a battery to loose so much of it's charge capacity. My 7+ still lasts me 3 days on a single charge.

[stj]

isnt this one of the phones with an eeprom in the battery protection that is checked against the central store of serial numbers?

in short - it will only work with a battery installed by apple - unless you keep the original protection curcuit or have a programmer.

[SMDFlea]

Originally Posted by stj

isnt this one of the phones with an eeprom in the battery protection that is checked against the central store of serial numbers?

in short - it will only work with a battery installed by apple - unless you keep the original protection curcuit or have a programmer.

Yes, afaik you need to swap the BMS board,activate the battery and program it

https://www.youtube.com/watch?v=NokIyI_J52I

[RethoricalCheese]

Originally Posted by SMDFlea

Yes, afaik you need to swap the BMS board,activate the battery and program it

https://www.youtube.com/watch?v=NokIyI_J52I

Not really. Swapping BMS is only needed to get it to show health and to not get that error message. Otherwise it works just fine without swapping.

They tend to get faulty dock flexes and sometimes there might be a shorted capacitor that causes it.
Unsoldering the applecake is the last thing to do here.

[AJ847.63e]

I’m thinking it’s the battery fpc connector on the board causing the issue. The far left pin seems a bit pushed in and loose so I’ve ordered a replacement. Still waiting for the board heater to arrive.

[diif]

If you've got bent pins I'd inspect the other connectors and sockets and lift the foam to double check you've not damaged any components.

Half right stj, the battery will work it displays a non genuine message and won't give proper stats.

[mon2]

Sharing a case of bad cap causing this issue.

[AJ847.63e]

Thanks for the advice all. The other connectors seem fine, both board and flex side, as do the caps near the connectors under the foam. Would it be worth putting the original battery back in to see if that charges?

Otherwise I did take out the taptic engine, charge port and speaker board so i could get to the battery strips so it's certainly possible the flex for the docks not correctly installed. If I tested for continuity between the charge port and the battery connector that should confirm the charge ports ok shouldn't it? Not sure if the dock connects directly to the battery, or if the two go their separate ways and meet in the middle therefore not giving continuity from the dock to the battery connector.

Definitely does present like a tigris or tristar issue though. My understanding is tigris controls the charging functions where tristar controls USB coms is that correct? It seems that the phone does not power on when connecting to the charger when battery is disconnected either so it looks like both are dead.

Is there any other diagnostics I can do before splitting the boards? I've ordered a pre heater but probably wont be here for a week or so.