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In this lesson we will talk about the BOOST chip

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The BOOST chip, also known as the auxiliary power chip,

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is designed to boost the voltage to 3.4V when battery power is below 3.4V

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Prevent sudden shutdown when the battery is low

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Because phones like the iPhone 6, 6s,

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At low temperatures, if the phone's battery drops below 20 percent,

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it will suddenly shut down without warning and won't be turned on

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Apple has addressed this issue by adding a BOOST chip to its iPhone 7 models

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to prevent sudden shutdown when the battery is low

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On Android, this feature has been available on very early machines

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The Xiaomi 4 model, for example, has this feature

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In the mainboard, it is not very good to identify

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need to use drawings or component map to identify

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Damage to the BOOST chip will cause the machine to fail to turn on,

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or to receive a high current

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When replacing the chip, you need to replace it with the same model

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Let's go to the real mainboard to see the BOOST chip

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This is the mainboard of the iPhone 8,

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and its BOOST chip is located in the upper right corner of the audio chip

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This chip is small, square, and we can't make out the size on it

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The board is an iPhone xs, and its BOOST chip is next to the hard drive, which is also square

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This is the mainboard of the iPhone 11,

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and its BOOST chip is in the upper left corner of the audio chip

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This chip is the BOOST chip

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Ok, that's all for this lesson