iPhone 6s will not boot fault repair
The customer sent us an iPhone 6s, and he said that his iPhone 6s could not be turned on.
We asked the customer if there was any anomaly when it was opened. He said that he charged before booting, but when plugged in the iPhone USB charger, he found that the charging icon appeared intermittently, the iPhone repeatedly flashed a few times and then a black screen, and then pressed the power button does not respond.
According to the customer's description, we could judge where is the problem proximately come from, which caused by charging. The three components Q2300, U2300, U4500, which are directly related to charging, according this direction, we start to repair.
Repair Steps
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!
We asked the customer if there was any anomaly when it was opened. He said that he charged before booting, but when plugged in the iPhone USB charger, he found that the charging icon appeared intermittently, the iPhone repeatedly flashed a few times and then a black screen, and then pressed the power button does not respond.
According to the customer's description, we could judge where is the problem proximately come from, which caused by charging. The three components Q2300, U2300, U4500, which are directly related to charging, according this direction, we start to repair.
Repair Steps
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!
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