Chosen Solution
Cleaned the phone with the ultrasonic bath. It came back, except touch doesn’t work. I’m new to microsoldering, so I’m unsure what’s wrong here. Is it touch ic?
I can see a lot of burnt components below the touch IC, I’ve seen a few boards that had corrosion under the IC but since you gave it a ultrasonic bath I don’t think it’s that. Replace those components with hot air and some flux. Try and see if it works :)
1st iMedic you must learn the schematics and use common sense. the touch circuit has two IC’s the 1st being a driver the second being a trackpad. before you join many in randomly pulling IC’s off the board with no clue what you are doing i would suggest you start with the power supplies first to the driver as the trackpad is controlled by the driver so no driver then no voltage. all water damaged devices fail when buck rails short as these are high ampere rails. low ampere rails or LDO’s rarely fail. the touch has a high voltage line 17v through the inductor coil and this must be the 1st place to check as it is a flyback generator. if you have pp voltages present at the driver and trackpad then consider replacing the driver then trackpad. to reball a water damaged device is nonsensical as the water damage is usually a short within the IC. the only thing you should ever reball is the parts that are non replaceable. the modem and cpu. if you reball you can not be certain you have eliminated a possible cause. the only way to do this is to replace. to avoid pop corning the cpu (blowing the balls) then recreate a temperature profile by bringing the board up to heat gradually and heating the ic for no longer than 10 seconds in one spell. keep a temperature profile that is gradual until the ic releases and you won’t go wrong
