Chosen Solution
Hi , i did a water damage repair of the backlight ic on this 6s which went well phone is working again ,, but i didnt realise it was fake charging , i have tried a new battery and , dock , still the same , i have changed tristar chip , still the same , i just got a usb amp meter and it showed around 1 amp current draw for around a minute then dropped to 0 the battery percent did rise from 65% to 68 % then jumped to 75% so seems a bit all over the place , i have tested P_IN on tristar it is 5v and PP1v8_SDRAM it is 1.8v im not sure where to go next ,
What about PP3V0_TRISTAR; what voltage are you measuring? Have you checked R2400 which is inline on TIGRIS_TO_BATTERY_SWI? On the older models there used to be a filter. If it is dislodged or damaged, you will have this kind of erratic charging. Does iTunes properly recognize the phone and have you tried to do a backup/sync to see if the communications work fully? Remember that Tristar is above all else a communications chip, not a charging IC. The real charging is driven by TIGRIS (via the SWI line) which is itself controlled by the CPU. I would also test the TIGRIS circuit completely if the above hasn’t solved your problem.
