Dead, no power. All voltage rails test good

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iPhone 6

Repair information and guides for the iPhone 6 that was released on September 19, 2014. Model Numbers: A1549, A1586, and A1589

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Stephen Elliott @mdrecovery

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Posted: Feb 2, 2017

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Dead, no power. All voltage rails test good

So looking for a motherboard specialist who can possibly shed some new light/ideas for me. I'm working on this iPhone 6 that is completely dead. Doesn't recognize plugged in or unplugged w/ good known screen and battery/charging port.

Weird thing is I've literally tested just about every voltage rail from vcc_main to pp_cpu and pp_gpu to 3v0_tristar and literally about 15 other main ones. All test short free and correct voltage.

Phone is not liquid damaged.

Any possible guesses or other ideas to try? I've already replaced pmic twice as well for giggles w/ no improvement.

My next step is to look into bl driver as from my experience this can cause goofiness but once again, incoming and outgoing from that bga test perfect.

Thanks.

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sir

will u please help me to trace dead iPhone

Jun 4, 2017 by Tech Electronic

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Minho @refectio

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Posted: Feb 2, 2017

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Hi Stephen. When you say you tested the rails, did you measure their resistance to ground or did you measure the actual voltages? You talk about the backlight...does iTunes recognize the board with only a battery and charge port connected?

There is a very real possibility that you have a defective major IC or broken traces within the board.

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Unfortunately iTunes doesn't recognize board. I've had iTunes sometimes not even recognize the phone when its just a backlight problem...weirdly. I tested both continuity to ground as well as actual voltages. I believe your right and suspected trace damage.

Feb 2, 2017 by Stephen Elliott

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Unfortunately iTunes doesn't recognize board. I've had iTunes sometimes not even recognize the phone when its just a backlight problem...weirdly. I tested both continuity to ground as well as actual voltages. I believe your right and suspected trace damage. — Stephen Elliott