Chosen Solution
Hi guys, I have a iPhone SE here. It’s water damaged, totally dead. When connecting to power supply, before pressing the power button, the phone immediately got about 50ma of power. After pressed the power button, nothing happened, the power stayed at 50ma. It looks like something is wrong in the PMU or the circuits around it. I checked through the board, no short found. I checked the caps around PMU, I found the resistance value of the PP_VCC_Main line is a bit too small (about 170 ohm), but is far from being shorted, using freeze spray doesn’t help in such case. I injected 4.5V into PP_VCC_main, didn’t find anything unusual. The board is cold even with 4.5V of power into vcc_main line. I didn’t feel any warm anywhere. Apart from VCC_Main line, the resistances of the output lines of the PMU look ok. I don’t know where to check next. Any idea would be appreciated. Thanks.
Sometimes water damaged phones do this…they are just stuck very early on in the boot process, draw little to no current and the device is just dead with no heat signatures. Those are tough to troubleshoot. You could try reballing IC’s in the area with the most liquid damage, try replacing Tristar etc. I would also look at I2C readings. You really should start using diode mode readings as that is what pretty much the entire repair community is using , they’re much faster and it makes “comparing” values more straightforward (i.e. ZXW, WuJinXi, other techs). I will revert to standard resistance measurements when I have a doubt about a diode mode reading (i.e. super low readings).
Try out these methods and see if they are any of help. https://www.wikihow.com/Repair-an-iPhone…
