Chosen Solution

Hi I got an IPhone 6 plus water damaged and came with short on VCC_Main Cap near the Audio IC. After removing the shorted Cap the phone works normally, but then after a few days the phone came in with with a new issue : .

  1. Always restart itself
  2. Battery percentage is not normal, like sometimes 80% and directly decrease to 5% and suddenly it turns off. . So I take a further step by changing the Charging IC (U1700). After changing the Charging IC the IPhone works well, but just for a few hours the issue CAME BACK (but the percentage issue is solved). Diode Mode on Vcc_Main looks normal to me around 350. . So my question is, do I need to change the Tigris Chip ? Is it possible that the issue came from the CPU ? What should I do next

It seems to me like you are just guessing at what the problem is. That can work, sometimes, as there are typical failure points but the issue is that every time you apply heat to replace an IC, you are risking collateral damage. A restart issue can be caused by a lot of things and Tigris is really only used for charging, which you repaired. So changing Tigris for no reason is not a good use of your time. Have you properly decontaminated the logic board? If you have, then start probing the PMIC / BBPMU outputs and compare to a known-good device. Then check the I2C and RESET lines to see if anything weird is going on.

Stop doing “Wheel of Fortune” repair i.e. “maybe the problem is….(spins a spinner)….THIS chip is bad”

Look at the schematic—-does tristar (U1700) talk to the battery at all? Why are you changing tristar if your problem is battery data?