When an iPhone 7 is slammed to the ground, the damage can be severe, affecting not only the screen but also internal components. In this guide, we’ll walk through the process of diagnosing and repairing an iPhone 7 serious drop damage, rendering it unable to boot. From addressing display issues to resolving baseband problems, this step-by-step guide will help you restore your iPhone 7 to full working order.
Phone Details:
Model: iPhone 7
Announced: 2016, September 07
Defect Phenomenon
The iPhone 7 was slammed to the ground during an argument, resulting in a shattered screen and the inability to boot.
Troubleshooting to Repair iPhone 7 Drop Damage
1: Initial Inspection
- Disassemble the phone and carefully remove the motherboard for inspection.
- The motherboard appears to be in good condition with no visible deformation or missing components.
2: Screen Replacement and Testing
- Replace the shattered screen with a new one and attempt to boot the phone.
- The boot current is normal, but the screen remains blank, indicating a possible issue with the display circuit.
3: Diagnosing the Display Circuit:
- Measure the diode values on the display connector. One pin shows an abnormal diode value of OL (open loop).
- According to the bitmap, this pin is connected to L3902, indicating a problem with the combined inductor.
4: Repairing the Inductor
- Remove the black glue on the surface of the inductor.
- After removal, the diode value on the inductor pin is 512, confirming that the inner rail is broken.
- Instead of replacing the inductor, which could cause soldering issues due to the number of connectors, jump a copper wire to repair the connection.
5: Completing the Display Repair
- Use the red-circled points to jump a wire, reconnecting the display signal (90_MIPI_AP_TO_LCM_DATA0_P).
- Apply a UV mask and cure it with UV light to secure the connection.
- Reassemble the phone and test it again. The phone now boots normally, and the display functions properly.
Addressing the Baseband Issue
1: Identifying the Problem
- After the initial repair, the phone boots, but there is no service, which is a common issue in iPhone 7s after serious drops. This typically points to damage in the Baseband PMU or Baseband CPU.
2: Repairing the Baseband PMU
- Remove the protective sticker to access the Baseband PMU chip.
- Apply solder paste and use a hot air gun to carefully remove the chip.
- Reconnect the broken wire using a soldering tin ball and resolder the Baseband PMU chip in place.
3: Final Testing
- Clean the motherboard with PCB cleaner to ensure all components are properly soldered and free of debris.
- Reassemble the phone and test it again. This time, the phone successfully recognizes the SIM card, and the “No Service” issue is resolved.
Conclusion
Repairing an iPhone 7 serious drop damage is a multi-step process that requires careful diagnosis and precision. By addressing both the display circuit and the baseband issues, you can restore full functionality to your device. If you encounter similar issues, follow these steps to effectively repair and revive your iPhone 7. For more detailed repair tutorials, visit REWA Academy and enhance your technical skills.
