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The maintenance of iPhone startup constant current and current jump faults

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In this lesson, we mainly explain the maintenance methods of these two faults

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Although the symptoms of these two failures are different,

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their maintenance procedures are the same

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Step 1 of the maintenance process, replace the external components,

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and eliminate the external components problem

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Because in mobile phones, many external components are detected through the I2C bus

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The external cables detected through the I2C bus include tail plugs cables,

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earpieces cables, boot cables,

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and wireless charging cables

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Most of the components on these cables are detected through the I2C bus

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If these cables are corroded by water or have problems,

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it will cause constant current or current cycle jump

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Generally, when we exclude external components,

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we can remove the mainboard and test the bare board

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If the current is normal after starting up,

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we can install these external components in sequence

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If it doesn't turn on after buckling which accessory,

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it means that the external cable is damaged

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Let me show you how to do it

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After disassembling, directly buckle the adjustable power supply

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If you find that the current cycle jumps after starting up,

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and it does not start up, or the white apple restarts

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We need to remove the external components to test the bare board

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For example, we remove all the cables,

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boot cable, screen cable, tail plug cable, etc.,

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and then turn on the power

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If short-circuiting the switch with tweezers is not easy to operate, the switch cable can be left

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If the current jump is normal at this time,

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it means that it is caused by external components

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We put the external components back one by one,

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if the current is not normal, it means the mainboard problem

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At this time we need to overhaul the mainboard

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Ok, that's all for this video