Today we will share a repair case of an iPhone 11 with no backlight.
First of all, we install the motherboard. Connect the screen and battery. Press the power button to turn on the phone. The Apple logo is vaguely visible. The phone can be turned on but the backlight is not working.
Remove the screen and disconnect the battery. Measure diode values of pin 26, 24, 22, 20, 18, and 16 on J8000 with diode mode of the multimeter. Pin 24 and 18 have no diode values. The normal value should be around 400-500. It can be preliminarily judged that the circuits of the two pins have open circuits.
Since relevant components of the two pins are under the shielding cover, we need to remove the shielding cover.
Protect the connectors with high-temperature tape.
Heat the shielding cover with Hot Air Gun at 380 °C and airflow 60. Pry up the shielding cover with a Sculpture Knife.
It can be seen under the microscope that R5651 and R5661 are burnt out.
Then we need to replace the two resistors.
Apply some Paste Flux. Remove the resistors with Hot Air Gun at 360 °C and airflow 40.
Apply some middle-temperature Solder Paste. Keep heating with Hot Air Gun. Because we haven’t found resistors of the same size, we use the iPhone 7 backlight protection inductors for alternatives. Heat with Hot Air Gun to solder the inductors.
After the motherboard has cooled, remove the high-temperature tape. Measure with multimeter. The diode values of pin 24 and 18 return to normal.
Next, we install the motherboard. The phone can be turned on. The display is working properly.
iPhone 11 no backlight has been successfully repaired.
Watch the below video to see how we fix iPhone 11 with no backlight.
Apr 23, 2021
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