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Recognition and Measurement of Electronic Components

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This video mainly explains the common crystal oscillator models

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and fault phenomenon of iPhone

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There are many different models and crystal oscillators with different frequencies

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in the mobile phone mainboard

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There is a 32.768KHz crystal oscillator in the mainboard

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This crystal oscillator is mainly connected to the main power supply

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to provide a reference clock for the internal RTC circuit of the power supply

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If it is damaged, the phone cannot be woken up,

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the time is inaccurate, and the time cannot be saved

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In electronic products, as long as the time-keeping crystal oscillator is used,

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the crystal oscillator with a frequency of 32.768KHz will be used

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Such as mobile phones, laptops, air conditioners, washing machines, etc.

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As long as it shows time, a 32.768KHz crystal oscillator will be connected to its circuit board

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The 24MHz crystal oscillator is mainly connected to the CPU,

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which provides the reference frequency for the clock circuit inside the CPU

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After the clock circuit inside the CPU receives the 24MHz frequency,

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it will provide a clock signal for the CPU or the chip managed by the CPU,

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such as the CPU itself, audio, camera, etc.

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If this crystal oscillator is damaged, the phone will not turn on, or the unit circuit will fail,

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such as the camera cannot be turned on, the audio will not work, etc.

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The 38.4MHz crystal oscillator is generally connected to the baseband power supply,

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but there are some special cases

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This crystal oscillator is to provide the reference frequency

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for the clock chip integrated inside the baseband power supply

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After the clock module inside the baseband power supply has a clock,

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it will convert the clock and provide a clock signal for the chip used for making calls

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If it is damaged, it will make it impossible to make calls,

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or there will be no 4G/ 5G signal, etc.

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iPhones use basebands from different manufacturers,

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and basebands from different manufacturers use different crystal oscillators

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iPhone 6 to iPhone 7 plus, Qualcomm baseband, using 19.2MHz crystal oscillator

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iPhone 8 and above models use a 38.4MHz crystal oscillator

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The baseband of iPhone 7 to iPhone X Intel baseband uses 26MHz crystal oscillator

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Therefore, we must pay attention when we overhaul,

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different models use different crystal oscillators

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Ok, that's all for this video