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Guide: New Solution for iPhone 7 Frozen Screen Issue

September 16, 2016 was the release day of iPhone 7, and some users complained about the frozen issue after the iPhone 7 dropped down. However, even the reinstallation by professional phone repair technician does not help the iPhone frozen problem once and for all. It is said that the iPhone frozen problem is caused by the iphone 7 production process, which can be solved by the audio circuit maintenance. In this article, vipfix will provide a new repair solution regarding iPhone 7 logic board maintenance! We hope it could be helpful to all iPhone repair technicians.

1. Turn on the iPhone 7, we found the screen is stuck off and power button responses very slowly.

2. Tear down the iPhone and disassemble the display assembly. Replace with a new iPhone 7 display assembly.

3. Now we try to turn on the phone again and test. The screen is still stuck off.

4. Enter the record mode, the record icons are in a non - functional state. Screen replacement is not helpful to the stuck problem, we can see that there is a problem in the audio circuit. Now turn to the iPhone 7 logic board repair.

5. Tear off the shield sticker on the iPhone logic board.

6. Some BGA solder is required to apply around the iPhone 7 AUDIO IC, then use a hot air gun at 300 degrees. Now the audio integrated circuit is removed.

7. Use a soldering iron with rosin to clean tin. And take solder wick for the repeat cleaning. After that, use PCB cleaner again.

8. Use a digital multimeter to test Pin C12 value (u3101 audio IC). The resistance value is swinging.

9. Take out WUXINJI schematic diagram for reference. The signal of the pin: 12s-ap-to-codec-mclk C12. The signal and CPU pass through the resistance r1103.

10. Scrape the insulation varnish off the copper wire connecting pin C12 and resistor R1103. Solder tins and then solder the 0.02mm copper wire.

11. Apply some UV curable solder mast to the soldered copper wire, place logic board UV drying lamp for 15 minutes.

12. Take the BGA reballing stencil to reball the iPhone 7 audio IC

13. Some BGA solder paste is injected into the weld plate. Then the audio IC at the right place, blow it with a hot air rework station at 280 degrees

14. Once the logic board is cool enough, use the PCB cleaner to clean it.

15. Assemble the phone and test.

16. The touch function and the recording function are restored to normal.

More professional cell phone repair tools and skills you need, please ask VIP FIX Shop Team for help on !


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