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iPhone audio circuit repairing

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This video mainly explains the working principle of the main audio from iPhone 8 to iPhone XS Max

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The first step of the working principle,

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when the battery is buckled or the adjustable power supply is connected,

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the BOOST boost chip will generate BOOST power supply

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This power supply will provide the first working voltage for the main audio

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Step 2, when the power is turned on,

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the main power supply will output more than 30 channels of power supplies,

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of which there will be 3 channels of power supply to provide working voltage for the main audio

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Step 3, during the process of starting the system,

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the CPU will send the MCLK clock signal to the main audio

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Step 4, after the CPU sends the clock signal,

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it will send a reset signal to the main audio

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Step 5, after the CPU sends the reset signal, it will send the start signal to the main audio

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Step 6, after the main audio has power supply, clock, reset, and start signals,

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the CPU will identify the main audio chip through the SPI bus

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After the identification is passed, the main audio can work normally

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Step 7, when there is audio data that needs to be converted by the main audio,

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the main audio first sends an INT interrupt signal to notify the CPU

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The CPU will send audio data to the main audio through the I2S bus

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After the main audio receives the data, it goes to codec processing

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These signals are the necessary operating conditions for the main audio to work

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If one signal is not normal, the main audio will not work,

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which will cause no sound failure

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That's all for this video