not charging... no 3.3v... power manager?

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iPad Air Wi-Fi

The wi-fi only version of Apple's iPad Air, model number A1474. Available in Space Gray or Silver, it packs the custom A7 processor and ships in 16, 32, 64, and 128 GB configurations.

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Dolcebimbo72 @dolcebimbo72

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not charging... no 3.3v... power manager?

Hi guys... I', struggling trying to solve an issue with this iPad Air...this is the scenario: while off, when connectin lighting cable it switches on but it does not charge the battery... what\s weird is that there is no "not chargin" message near battery icon... simply nothing.

Analyzin with multimeter there are no shorts at all in the board, but 3.3 volts rail is completely missing..... all the other voltages are present. I tested continuity between dock pins soldered to the board and checkpoint and everything is ok... I already replaced the charging IC (U6000) but no result.... each and every smd belonging to PP3V3_ACC line is good and functional... should I replace the power manager (U8100) or anyone of you can suggest me other solutions? thanks everyone in advance....

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Minho @refectio

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The PP3V3_ACC line is only present when the phone powers on. Otherwise, unless there is an accessory plugged into the Lightning port, you don't need to worry about it.

Did you check all the rails generated by the PMIC, there are a few dozen?

Perhaps your Tristar replacement did not succeed and you should try it again.

EDIT

This is the Tristar circuit. Check the following voltage rails

PP3V0_S2R_TRISTAR

PP1V8_S2R_TRISTAR

PPVBUS_PROT

(but not PP3V3_ACC)

You should be able to find the schematic on the web

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and could you tell me what are exactly the rails to check, the ones involved in battery charging process?

Dolcebimbo72 의 2016년 12월 8일

the voltage rails you mentioned are present... I thought the problem was in PP3V3_ACC just because battery is not charging.... so confused :-(

Dolcebimbo72 의 2016년 12월 8일

As I said, perhaps your Tristar replacement did not succeed. You should also check all the PMIC rails, the problem could be elsewhere. Good luck!

Minho 의 2016년 12월 8일

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and could you tell me what are exactly the rails to check, the ones involved in battery charging process? — Dolcebimbo72
the voltage rails you mentioned are present... I thought the problem was in PP3V3_ACC just because battery is not charging.... so confused :-( — Dolcebimbo72
As I said, perhaps your Tristar replacement did not succeed. You should also check all the PMIC rails, the problem could be elsewhere. Good luck! — Minho

iPad Air Wi-Fi

not charging... no 3.3v... power manager?

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