In our previous article, we have revealed how to troubleshoot and fix iPhone no display. And in this article, we will share how to fix iPhone 6 no backlight/black screen with chip level repair. Hope you enjoy our sharing.
Step 1 Function Test
In high exposure shooting mode, we found that the iPhone has display function but lacks of backlight, besides, when the motherboard is powered on, the DC Power Supply shows too high current, which indicates current leakage. According to our analysis, it is caused by the backlight power supply.
Step 2 Troubleshooting
Use the multimeter to measure the diode resistance of the display connector pin 2, 3, 6, and the display connector pin 2 showed open circuit, nevertheless, the line between FL2024 to display connector pin 2 is also showed open circuit.
Step 3 Diagnosis
There are traces of combustion oxidation when observe under the microscope, indicating that the line is broken and needs to be reconnected by operating jumper wire.
Step 4 Repairing
First apply solder paste on the display connector pin 2, solder one of the cooper wire end to the display connector pin 2 by using the soldering iron, then solder the other cooper wire end to the inductor FL2024. Don’t forget to clean up with the PCB cleaner when finish.
Finally, apply a thin layer of UV curable solder mask on the jumper wire and cure with the UV curing light for 1 minute.
Step 5 Final Check
Reassemble the motherboard, connect to power and boot up, all function works well, repair completed.
Please refer to below detailed video:
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Tools and Materials Used in This Video:
DC Power Supply
Solder paste flux
UV curable solder mask
UV curing light