The customer sent us a faulty iPhone 6s, and he said his iPhone 6s could not be turned on. He tried to charge before turning it on, but when plugged in the iPhone USB charger, he found that the charging icon appeared intermittently, the iPhone flashed several times and then it was black, then the power button did not respond.

Based on the customer's description, we can judge the location close to the problem, which is caused by charging. The three components Q2300, U2300, U4500, these are directly related to charging, in this direction, we start repairing.

The first step we should take is to connect it to the DC power supply and test the current, the trigger current jumps directly from 200 A, while the normal current should be around 40 mA. This phenomenon is likely caused by a short circuit in the mains supply's LDO supply.

PP3V0_TRISTAR, PP3V3_ACC this two are supplied by all LDO power supply, so the most likely damage is the USB U4500 IC. Remove the USB IC with QUICK 861DW Hot Rework Station, trigger current about 40mA, then replace the USB IC.

After replacing the iPhone USB charging IC, turn it on and test it, then boot into the system and the iPhone can be charged normally. The fault has been completely solved!

If you need any help,please contact us on www.vipprogrammer.com.