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Guide: How to Repair iPhone 7P Backlight Failure

We are going to fix the backlight problem on iPhone 7 Plus, before repairing, we need to check the schematic diagram on WUXINJI Dongle, there are two sets of backlights, one is on the left of the iPhone display screen, and the other is on the right of the iPhone screen, they are controlled by light boost IC-- A and light boost IC--B.


The light boost IC--A controls the backlight on the right side of the screen, it controlled by three sets of signals: PP_LCM_BL_ANODE (10.5V cathode power supply),PP_LCM_BL_CAT1 and PP_LCM_BL_CAT2. If these three sets of signals don't work or the light boost IC-- A damage will cause iPhone right screen won't light.

The light boost IC--A external two sets of diodes and boost inductors, the iPhone 6 only have one set, and because the iPhone 6S has one more function, the iPhone front camera comes with flashlight, so this front flash light is provided by the newly added set of rectifier diodes and boost inductors. If one of these is damaged, then it will cause boost light IC--B was burned, you have to replace it.

The light boost IC--B controls the backlight on the left side of the iPhone display screen, it controlled by three sets of signals: PP_LCAM_BL34_ANODE(10.5V cathode power supply), PP_LCM_BL_CAT3 and PP_LCM_BL_CAT4. If these three sets of signals don't work or the light boost IC-- B damage will cause iPhone left screen won't lit.

The light boost IC-- B external two sets of diodes and boost inductors, the iPhone 6 only has one set. Because iPhone 6S has one more function, its front camera comes with flash light, and it is provided by the newly added set of rectifier diodes and boost inductors. So, if one of them is damaged, it will cause boost light IC--B was burned, you have to replace it by using QUICK 861DW and Precision Titanium Alloy Tweezers.

The boost inductance of the lighting part is integrated in an IC (Inductive integrated IC), this IC integrates the inductance for lighting part, the display part, the charging part and the ring-tone part. The damaged inductive integrated IC will cause iPhone no backlight no display issues, and will cause iPhone no charge, no ringtone and no vibration failures.

More professional iPhone repair tutorials, please contact us on www.vipfixphone.com

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