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iPhone audio circuit repairing

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This video mainly explains the working principle of iPhone video recording

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The principle of video recording is the same for iPhone 8 to iPhone 12 ProMac models

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Step 1, after opening the front camera and clicking the record button,

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the microphone 3 connected to the earpiece cable will collect the sound signal,

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and the signal will be sent to the big audio

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Step 2, after receiving the sound signal,

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the big audio will convert the analog signal into digital audio data through the internal circuit,

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and send it to the CPU through the I2S bus

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Step 3, after the CPU receives the digital sound signal,

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it will integrate the sound data with the image data collected by the camera,

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and then transfer it to the hard disk through the PCIE bus

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When the iPhone is pressed to stop video recording, the CPU stops dumping

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At this time, the video recorded by the front camera will have sound

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When the video recorded by the front camera has no sound,

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we need to overhaul the earpiece cable,

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the earpiece connector to the big audio line, and the big audio to the CPU line

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Next, let's learn the principle of rear camera video recording

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When we turn on the phone camera function, switch to the rear camera

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After clicking the recording start button,

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the MIC2 connected to the boot base will first collect the sound signal and send it to the big audio

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Big audio converts the received analog sound signal into a digital signal

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and sends it to the CPU through the I2S bus

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After the CPU receives the digital sound signal,

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it will integrate the sound data with the picture collected by the rear camera,

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and then transfer it to the hard disk through the PCIE bus

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When we press the stop button, the CPU stops dumping

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At this time, the video recorded by the rear camera will have sound

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When the video has no sound,

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we need to check the line from the microphone 2 to the big audio

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That's all for this video