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The April 2014 update of Apple's 13" MacBook Air features refreshed dual-core i5 and i7 processors, plus slightly increased battery performance.

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Overheating capacitor on logic board, not turning on.Possible reasons?

Hello!

Recently my father tried to turn on his MacBook Air 13” Early 2014 MD760LL after leaving it for charging, and it did not turn on anymore. There was no physical or liquid damage. I tried battery and SMC reset, but it didn’t solve the problem. When connected to power, orange light is on whole time.

I disassembled the case and found out capacitor is overheating and smells burned when board connected to power (after some time smell goes away). But visually it looks fine, no burned signs on the whole board. In schematic book I found this capacitor is called C7323 (pics below, where I marked exact one in case I took wrong pdf). I think, it is one of the first capacitors in line after power input from io board (I’m not really good at schema reading), because it is physically positioned close to it.

It would be great if somebody could say possible reason and what to look at. I have multimeter, so can check something. Hope it is some common thing :)


Merry Christmas!

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Many kinds of capacitors fail in a short circuit. The capacitor is likely shorting the power rail and preventing the system from starting. The capacitor in question looks like a filter capacitor, my suggestion would be to remove it and see if the system will start without it (its usually fine to remove filter capacitors temporarily). If the system turns on then go ahead and use a schematic/boardview to find an equivalent and replace it.

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Hi! Thanks for the answer! Could you please tell me is it possible to check capacitor using multimeter? Currently do not have an option to unsolder it and in schema it marked as "critical" (added pic to topic)

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The best way will be measure in resistant from one side of the capacitor to the other. They usually fail full short (>1 ohms) but I've also seen partial shorts occur. Due to the circuit powering the CPU its possible its also a low (but not 0) resistance so be sure to compare the measurements from ground to C7323 and ground to L7320 (L7320 Should be higher even if not by much)

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Thanks! Found same capacitor from other mac and resoldered it. It works :)

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Antony Iv будет вечно благодарен.
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