SOLVE:iPhone 6 can’t boot but Voltage shows Stably
"Why iPhone 6 can’t boot but Voltage shows Stably " a customer saied. When iphone can’t be turned on, you life will become very awful. But don’t lose heart, vipprogrammer will help you tide over difficulties. Now prepare the iphone repair tools to start.
Trouble Phenomenon:
The iPhone has been dropped in water and is short circuit. After removing some capacitors, the leaked current is 200mA. After replace power chip U1201, it does not leak any more but it cannot be turned on. Current jumps repeatedly from 110mA to 130mA.
Repair Process:
1. Most of the case, this problem is often caused by faulty circuits in touch screen chip U2402, power chip U1202 and CPU upper board.
2. As customer replaced power chip before, we replace its power chip to exclude the solder problem.
3. But the turn on current is still jumps repeatedly from 110mA to 130mA. According to the experience, in watered iPhone, the damaged upper temporary storage is caused by chip short circuit itself.
4. Observing the temporary storage and the surrounding area of CPU under microscope, we can see explosive tin balls on the surrounding area of upper temporary storage. Now iPhone can be turned on normally. The explosive tin balls on upper temporary storage.
5. When it was first fixed, CPU shield cover was not move, so we did not check the explosive tin balls on it. For those chips that have been removed or replaced by other maintenance men, we had better check whether the explosive tin balls appear in CPU or temporary storage chip on the upper board of CPU.
Trouble Phenomenon:
The iPhone has been dropped in water and is short circuit. After removing some capacitors, the leaked current is 200mA. After replace power chip U1201, it does not leak any more but it cannot be turned on. Current jumps repeatedly from 110mA to 130mA.
Repair Process:
1. Most of the case, this problem is often caused by faulty circuits in touch screen chip U2402, power chip U1202 and CPU upper board.
2. As customer replaced power chip before, we replace its power chip to exclude the solder problem.
3. But the turn on current is still jumps repeatedly from 110mA to 130mA. According to the experience, in watered iPhone, the damaged upper temporary storage is caused by chip short circuit itself.
4. Observing the temporary storage and the surrounding area of CPU under microscope, we can see explosive tin balls on the surrounding area of upper temporary storage. Now iPhone can be turned on normally. The explosive tin balls on upper temporary storage.
5. When it was first fixed, CPU shield cover was not move, so we did not check the explosive tin balls on it. For those chips that have been removed or replaced by other maintenance men, we had better check whether the explosive tin balls appear in CPU or temporary storage chip on the upper board of CPU.
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