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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 bootloops when Audio IC is in

Hi, I got some “dead” motherboards to repair and I have problem with this one. It is A1778 model. It was missing some chips (BB PWR, Tristar and Audio IC), so I replaced them.

Without audio IC it was working fine, got signal and everything, but when I put audio IC back the phone starts bootlooping. I have done jumper wires, tried another chip, but it is always the same. Any ideas where might be a problem?

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Have you ruled out parts? Installing the audio IC can bring into play the front camera flex assembly, faulty battery and dock connector. If you are sure it is not a parts issue you can continue diagnosing the board.

·         Have you tried a different batch of audio IC’s?

·         Are you re-balling them?

·         You need to diode the pads under the IC and compare with a working board.

·         Have you checked all the resistors under the edge of the shield? They can occasionally get nudged.

·         The most important one is have you jumped D12 to G12 and tested?

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