diyphonetool的部落格

Fault Description: iPhone 6 Wi-Fi can't be turned on while displays grey.

Fault description: iPhone 5S fingerprint happens intermittent faults

We may need to disassemble it and get the home button, check whether the IC happens fault, then let us start.

The charging problem is not strange for us, but if it really happened on you, it will be a frustrating thing. The power drains fast and you can't do any long time process on your device,  so it is still necessary to repair it.

Fault description: iPhone 6S Plus occurred touch panel fault 

According to our ever experience, it is great possibility to be caused by IC fault. If you are clear about this part, you may just need to change it,  let us start today's analysis.

After read the email, we know jason has shipped his iPhone 7P to us as for the backlight fault.

After experiencing so many phone fault, we have already recorded too many case in our notebook. 

Fault Description: iPhone 6P can't turn on.

After each phone was sent to us, we will ensure the fault and check which tool we will use. Of course, we also have dealt similar fault like this, but same fault don't mean the same sources fault. We still need to check it carefully.

According to the attached file, we know there exist a unresponsive when plug in charger and we also have checked the charging interface, no anything shows in it.

We direct test the battery seat voltage B+ with Fluke 15B+ Digital Multimeter, it displays 0.46V, there is no voltage can directly exlcude the battery problem. Test battery resistance B+385 which shows normal, disassemble the single board. There exist a test point below the battery interface, if the value shows 5V, it means there no problem with the tail plug. So we have to continue the testing.

After we confirmed the fault, the first step we do still is to check the current and find which components caused the fault, the detail repair process as following:

The PP1V8_UT (1.8V), PP3V0_UT_SVDD (3.0V) can be measured after turning on the iPhone 7 device, however, the PP2V8_UT_AF (2.8V, PP2V9_UT_AVDD aggregation voltage) (2.9V), PP1V2_UT_VDD (1.2V) these three circuits of power supply only can be measured when the iPhone 7 camera under good state, the PP2V9_UT_AVDD circuit power supply is provided by the U2501, the U2501 is very easy to cause camera working abnormally. The best solution is to take the U2501 off and short connect by jumper wire to solve the problem.