Chosen Solution
Guys im lost here. I have done a lot of iPhone 7 and 7+ sound ic, guessing around 100, the thing is, for some, the following happens 1 iPhone will boot normally, albeit a little slower. 2. Sound that was not working before works perfectly 3. It does not charge properly, it starts ok at normal amps then drops to 0, the battery % jumps after every reboot and sometimes when the iPhone is being used. 4. The battery shows as maintenance, with no health meter, the battery before had like 90% health. 5. I have tried new charger, new battery, turned it on off the hosing, redone the sound ic fix 4 times and still same problem. 6. I have had this problem like 5 times and one time it solved itself when I put all these screws etc back. Others when I redid the sound ic Any help to what the !&&* is going on will help a lot guys, thanks for you’re time. Update (01/27/2020) SOLVED!! It was the battery connector, i removed the plastic middle part exposing the two metal connectors for SWI, added some solder also and it worked perfectly! hope this helps other that may have this issue.
Without seeing your soldering technique it would be hard for me to tell you where to look. You have said that this has happened about 5 times before which makes me think you should change your audio IC procedure. Are you reballing the IC’s? · If you are tilt the chip up and make sure all the balls are even. · Are you using solder wick on the IC,s? · Have the chips got small nicks in them from tweezers. First thing I would check is the VDD boost line. Are you getting any current draw before prompt to boot? How many jumpers are you running? Have you checked D12 and G12 pads it might pay to run a jumper between those. Erratic battery percentage would point to BATT_SWI line although I have seen a partial short on VDD_BOOST cause this problem.
