Released September 16, 2016. Model 1660, 1778 Available as GSM or CDMA / 32, 128 or 256 GB / Rose gold, gold, silver, black, and jet black.

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iPhone 7 not charging and bootloop

Hello there,

We have an iPhone 7 that is not charging, we have fitted a known good battery and connector port and the Apple logo appears. Two main things about this one are that:

  1. The device stays on the Apple logo and loops
  2. The device draws 0.00 Amps.

It only shows the Apple logo when we plug it in or press the power button.

I would start to suspect maybe a U2 issue but the device remains on the Apple logo so I'm not sure if this is contradictory.

Just wanting to know if anyone else has had issues like this and where to begin, I'll disassemble this fully and check for obvious signs of damage/shorts and report back.

Answered! View the answer I have this problem too

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it does sound like tristar problems

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When dealing with a “dead” phone, you have to start at the beginning and check PP_BATT_VCC, PP_VCC_MAIN and PP5V0_USB. I would start by checking to see if those rails are (partially) shorted to ground. If one of these rails is shorted to ground, then you will need to identify what is causing the short. It could be a bad decoupling capacitor, conductive debris or defective IC that is directly supplied by those rails.

If they are not shorted, then you can connect, preferably, a known-good battery (or a current limited DC power supply with the appropriate connector adapter) to see what voltage you measure. If the voltage is low or lower than the battery voltage (which you measured before plugging it in ;>), then there could be a short circuit on secondary subsystem that is causing the battery or DCPS to be current-limited.

If you are measuring the proper voltage, then you move onto the PMIC and check the voltage rails it generates.

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You are very helpuf in this, can you please provide a picture of the pinout of the places you are using to test the PP_BATT_VCC, PP_VCC_MAIN and PP5V0_USB?

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