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This lesson is about the maintenance of camera failure of not turning on

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When there is no abnormality in the above measurement, it is necessary to proceed to step 3

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Find the camera's clock signal

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Take Xiaomi 11 as an example

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For the camera J7202, its clock signal is at this position, connected to 24 of the connector

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Let's take a look at its line channel

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It leads to the inductor L3301, and then goes to the V5 pin of a chip after passing through 2 pins

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This chip is U3100, the model is SM 8350, which is Qualcomm's CPU

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It has a component in series from the connector to the CPU

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This clock signal generally comes from the CPU

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The line is generally connected to a zero-ohm resistor or inductor

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If OL appears during measurement, measure the pin on the end of it connected to the CPU

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For example, pin 1 of L3301 is connected to the connector

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Measure at the pin of the connector end, it shows infinity,

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then you need to find this pin to measure the ground value

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If there is a value to ground, then directly short the inductor to solve the fault

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If the ground value is still infinite, you need to re-solder the chip connected to pin 2

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It goes to the CPU, then the CPU needs to be resoldered

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Of course, if there is a short circuit on this pin, the CPU must be replaced

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This is the clock signal

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If the ground value of the clock signal is normal, it is necessary to measure the reset signal

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First of all, you need to know whether the reset signal comes from the CPU or the camera power supply

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If the measured ground value is infinity or 0,

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you need to re-solder the CPU or camera power supply

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If there is no problem with measuring the clock and reset signal,

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we need to measure the ground value of the I2C bus

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The I2C bus is generally connected to the CPU

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If the measured value is infinite or short-circuited to ground, you need to re-solder the CPU

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If re-welding can't be solved, it is basically irreparable

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That's all for this lesson