We are going to fix an iPhone SE device today, according to the owner's description, the main problem is that it fails to turn on, also , there is power leakage phenomenon. How should we solve this problem, let's check in the article!
First of all, open the iPhone SE and remove motherboard to test, the battery interface is the same as iPhone 6P, if there is no professional 6P DC power supply interface, you can also replace by ordinary alligator clip, as shown in picture 1-1.
The battery positive voltage VBATT is first sent to the charging IC-U2300, and the charging IC-U2300 outputs the main power supply VCC_MAIN (same as the battery positive voltage value) to the main power supply U2000 and other related circuits.
There are 3 situation you may encounter:
1. If iPhone SE is unresponsive after turning on, first measure whether there is the main power supply supplied by U2300, if not, you need to replace U2300, if the main power supply is normal, the problem is from the power IC or CPU.
2. if the current is small and iPhone SE is unavailable, measure whether the voltage of the parts as shown in WUXINJI schematic diagram is normal, as shown in 1-2, if yes, you need to replace the clock crystal Y0600, check and weld several pull resistance of bus circuit will cause small current and iPhone unavailable, these resistance must be replaced instead of short connection, if the above problems are excluded, it should be the iPhone SE CPU problem, you can install a new CPU to solve.
3. If the current is large when supplying power, it is usually caused by the positive voltage of the battery or the main power supply, which has short circuited parts. The large current can be quickly found with the rosin method. How to operate: At first, use digital multimeter to measure the battery positive pole and the main power supply to the ground resistance value, find out the short circuit parts. Use rosin to smoke the iPhone SE main board into white color, add voltage in the short circuit parts, you have to notice that the voltage must be added to the short circuit parts, the voltage is gradually increased from zero, after the short circuited parts is supplied power for a while, it will heat and turn into different color, then you can find the specific components immediately.
Any technical support for iPhone repair, please research on www.vipfixphone.com
First of all, open the iPhone SE and remove motherboard to test, the battery interface is the same as iPhone 6P, if there is no professional 6P DC power supply interface, you can also replace by ordinary alligator clip, as shown in picture 1-1.
The battery positive voltage VBATT is first sent to the charging IC-U2300, and the charging IC-U2300 outputs the main power supply VCC_MAIN (same as the battery positive voltage value) to the main power supply U2000 and other related circuits.
There are 3 situation you may encounter:
1. If iPhone SE is unresponsive after turning on, first measure whether there is the main power supply supplied by U2300, if not, you need to replace U2300, if the main power supply is normal, the problem is from the power IC or CPU.
2. if the current is small and iPhone SE is unavailable, measure whether the voltage of the parts as shown in WUXINJI schematic diagram is normal, as shown in 1-2, if yes, you need to replace the clock crystal Y0600, check and weld several pull resistance of bus circuit will cause small current and iPhone unavailable, these resistance must be replaced instead of short connection, if the above problems are excluded, it should be the iPhone SE CPU problem, you can install a new CPU to solve.
Any technical support for iPhone repair, please research on www.vipfixphone.com
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