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How to Fix Unknown Error (-1) on iPhone 6

The unknown error (-1)  is shown on iPhone 6, this phone is from one of our customers. He mentioned that the device turns no signal after replacing back cover, LCD touch screen, charge connector and other spare parts. How to fix this error?

Based on the above phenomenon, I narrow the problem to baseband. Checking the progress bar when rooting, I find that it reports error (-1) at the place of recovering firmware and now the progress bar is at about 50%. Tearing it down and testing, I find that baseband power supply PP_VSW_S3 is short circuit to ground. The circuit diagram of PP_VSW_S3 is shown in the picture.


It is still short circuit to ground after removing baseband power supply chip. The location of baseband power supply chip is shown in the picture.



Put rosin on motherboard and find that capacitor C3257_RF is short circuit. The material object of C3257_RF is shown in the picture.


PP_VSW_S3 power supply filter capacitor C3257_RF is short circuit. Remove it and short circuit disappears. The rooting goes on smoothly, as shown in the picture.


This iPhone has net lock and it needs to be inserted card to activate. But after activating, I find that Wi-Fi is still in problem. Wi-Fi address is unknown, as shown in the following picture. Wi-Fi icon is grey and cannot be turned on. Measure the working condition of each Wi-Fi circuit. They are normal. Replace WiFi chip. Trouble is removed.



More examples for practical cell phone repairs, and any equipment and tools you need to repair phones just check at www.vipfixphone.com

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