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1.8GHz dual-core Intel Core i5 (Turbo Boost up to 2.8GHz) with 3MB shared L3 cache

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Mac will not boot, has green light, can reset smc, nothing.

Hi There.

Glad to be here!

I have had this macbook air since 2012 and it has never skipped a beat. Until just one day it chose to not boot up.

I get a green light when magsafe is connected, I followed the steps to reset my smc and the light changes to orange then back to green. afaik this means it reset fine.

However holding power button, pressing power button. nothing. I get no fans, no noise, no display.

Not sure what to do now, I have removed the battery and it will not start with just magsafe either. So what else could be causing it?

just a side note, it's very unlikely to be water damage.

Thanks in advance.

Mike.

Beantwoord! Bekijk het antwoord Dit probleem heb ik ook

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Once you get the bottom cover off disconnect the battery and see if you can run the system directly with the MagSafe adapter.

Update (03/14/2018)

Here's the IFIXIT guide to take your logic board out: MacBook Air 13" Mid 2012 Logic Board Replacement

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that is most certainly my plan. will report back

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ok i have removed the battery and plugged in the magsafe.. still won't boot. Any ideas

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it's strange i removed the battery and no luck. however i removed the trackpad and turned the laptop over and all of the sudden the fan started.. but no display or beeps.

tried to recreate and no luck again. can't get it to even turn the fans on again.

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Did you have a liquid spill at one point? I'm suspecting the charging logic got damaged. As it turns out it sits on the back side of the logic board and can get wet if liquid spills into the keyboard.

I think its time to pull the logic board out and do a through inspection for corrosion and/or burnt components.

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def no liquid damage. I inspected the whole board and saw no signs of any burns or anything that indicates liquid damage.

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Is the heat sink screwed on tight? I’d recommend reinstalling thermal paste on the CPU and dusting off the vents and fans

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While I'll agree this system is due for a refresh of its thermal paste as well as a loose heat sink I don't see that as the issue here.

Yes, a good dusting out is a good idea, but, again it's not the issue.

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I thought it could be because a system unable to boot may be because of thermal problems.

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really? forgive my ignorance but could this stop it from booting? wouldn't that only cause issues after the system got hot? but a cold boot should be unaffected? unless i'm completed misguided on how macs work :D

one thing i should add that when i removed the trackpad and battery, i turned it over with it plugged in and the fan started randomly but there was no display... but then i could not reproduce it or get it to boot. guess logic board trouble shooting is the way to go.

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I’ve built PCs for a long time and have diagnosed and troubleshooted others for even longer.

If a thermal compound application dries out or is insufficient, the CPU can get incredibly hot within seconds. A good motherboard should detect that the CPU isn’t getting enough cooling and will prevent it from booting in the first place.

This actually happened to me because I accidentally used the wrong mounting hardware on my desktop CPU and even though I screwed it down really tight, it still wasn’t enough pressure to allow for good cooling. My system didn’t POST at all. I could hear the fans spinning for a few seconds and then shut off within 6 seconds.

Thermal conductivity is vital for all computer components. These things get incredibly hot

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thanks David i shall check it out!

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Mike Powell zal eeuwig dankbaar zijn.
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