We recently received an iphone 6 that was not charging. A new charging port and battery had already been fitted by another shop and not solved the issue.
We connected new ones and still the phone would not charge. We disassembled the phone and removed the shield over tristar expecting it to be a standard tristar failure. Everything seemed normal, to start with, no previous repair attempts, testing the lines showed 3v3 line power as normal but nothing on the 1v8 line. There were no shorts around the IC so we went ahead and removed the tristar charging ic.
Once removed we could clearly see why there was no power on the 1v8 line. The trace to pad F3 had totally burnt out and no longer existed. This was not a problem for us. We simply made a micro jumper from C1739 to the F3 pad to remake the connection. We then fitted a new tristar charging ic and tested the device, we now had power on the 1v8 line and had restored charging capabilities to the phone. We tested voltage coming into the battery connector and had 3.7V which is perfect.
We reassembled the device and sent it on its way back to its owner who was very happy with the repair. We had restored full functionality to the phone that they had been told could not be fixed elsewhere.
If you have a charging issue on your iphone or have been told somewhere else that your device is not fixable, please feel free to get in touch, we would be happy to help.