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Small startup current of iPhone

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In this lesson, we will focus on small current fault identification

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Small current means that when the mainboard is connected to the adjustable power supply,

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we trigger the switch

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The current displayed is relatively small

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Only tens or tens of milliamps, and the machine doesn't turn on

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This phenomenon is defined as a small current fault

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In iPhones, the startup current is different from different machines

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For example, the starting current of iPhone 6 series is about 70mA

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For iPhone 6S to xs max models, the startup current is about 50mA

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The starting current of iPhone 11 and 12 series is about 80mA

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Startup small current fault refers to the mainboard is energized,

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we trigger the switch, the startup current is between 0-30mA,

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which is a small current fault

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According to different models of the takeoff current is not the same,

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there are some differences in the actual judgment

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For example, the mainboard of iPhone 12 in the picture,

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its normal startup current is 80mA

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The small current fault of this model is that when we press the switch,

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its current is about 40/ 50mA, which is a small current fault

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Generally speaking, after pressing the switch,

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the current is less than half of the normal start current,

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it is a small current fault

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Now let's observe the physical mainboard small current fault phenomenon

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Let's look at the trigger current of the iPhone7

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After the switch is triggered, the current starts to jump from about 50mA,

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which is a normal current jump

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After the switch is triggered, the current is only 19mA,

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and it does not move, which is a small current fault

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Let's take a look at the iPhone X's current jump

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When the switch is triggered,

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the current jumps from more than 50 milliamps

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Let's look at the small current fault of iPhone X

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After the switch is triggered, the current is only 24mA and is frozen,

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which is a small current fault

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Let's look at the trigger current of the iPhone 12

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After the switch is triggered, the current starts to jump from about 80mA,

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which is a normal current jump

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After triggering the switch, the current is set at 47mA,

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which is a small current fault

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As we have just seen, if the starting current is less than half of the normal starting current,

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it is usually a small current fault

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So, that's it for this lesson