What on the logic board blew up? Why does it work now?

This is a strange one. I've had my macbook pro since late 2010, one month out of the extended apple care and boom... wont turn on. Seems a bit like a ticking time bomb, no?

Paranoia around planned obsolescence aside, something strange happened. My symptoms were hinting towards a logic board problem (battery charging ok, indicator turning orange when charging, only turning green when fully charged or doing SMC reset) still in any case never powering on, plugged into the mains or not.

Being out of warranty, I decided to open up my machine and take a look for myself. Sure enough, a capacitor or something had blown, taking a few things around it out too - see these pics:

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http://www.flickr.com/photos/104816644@N...

That whole area appears to control the battery interface with the logic board, so situation seemed a no go without a new board or some annoying soldering. (Anyone happen to know what capacitor this is supposed to be? incase I do have to repair?)

HOWEVER, I put my case back on, turned the machine over, opened the lid and it just... turned on. Like it was waking from hibernation.

What did I do? nothing. Unplugged the keyboard connector and put it back. blew away a little dust. You see from the pictures that this is a real hardware issue... so how on earth does it manage to turn on now!?

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It looks like the foam pad got the worst of it. You do have some damage to the logic board (exposed copper traces) and clearly something did get burnt, which started it all.

Even though its past your Apple care extended warrantee I would still see what Apple might do for you. Can you get to a local Apple Store? I would just tell them you smelt something burning inside, I wouldn't tell them you opened up the system, as you don't want them to use that as a reason for not fixing it.

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OT - Do you have a board layout for this model to ID the parts that are burnt?

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Yes I do. there are at least four components that may have "taken a hit" Biggest concern of course are the traces. If they are destroyed it may be salvageable with a circuitwriter pen and some good soldering skills. This will depend on the skills of the OP.

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Hi Dan! Thanks for the quick response. When you say OT, are you referring to me? (sorry, new to this board)... I do not have a board layout, I am trying to find one so that I can identify this part.

With regards to your other comments, I already have an appointment with apple for next week - I'm based in London, UK. Hopefully I can make it, I've been so busy with work lately that I've missed the last two appointments. The Apple Care ran out end of August... Typical.

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OT is just the guy who has a good collection of schematics and layout diagrams. The layout drawings are hard to find out their in the Ether of the Internet. As I don't do board level stuff any more I haven't spent the time or money to get qualified from Apple.

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Okay, all the pieces that "blew up" are part of your EXTRACTION NOTIFICATION CIRCUIT for your AUDIO: JACK TRANSLATORS circuit. That is the reason why it continues to turn on. It does look like some extensive damage. To further identify if it is possibly salvageable, clean the charred area with a soft brush and some isopropyl alcohol. Post an image after it is cleaned.

UPDATE

I used your image to at least give you a start. There are a few components that I listed as missing. Missing refers to me not seeing them on the image, they may still be under the soot:-)

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Reference designator Description

Q6802 TOSHIBA Field Effect Transistor Silicon N Channel MOS Type SSM6N15FE

R6861 Resistor 0ohm 5% 1/16W 402 package

R6865 Resistor 100K 5% 1/16W 402 package

R6864 Resistor 220K 5% 1/16W 402 package

C6861 Capacitor 0.1 UF 10V 20% 402 package

R6880 missing Resistor 100K 5% 1/16W 402 package

R6715 missing Resistor 0ohm 5% 1/16W 402 package

R6721 missing Resistor 100K 5% 1/16W 402 package

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Wow, that was fast! Oldturkey, thanks so much! If it is part of the extraction notification for the Audio, how comes I have no issues whatsoever with those functions? Furthermore, why did my machine not turn on for so long? Was that just a coincidence?

I will clean up and post a new pic tonight if I have time. Possibly tomorrow.

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Kyle, all the components that may have gotten damaged are part of that circuit. This does not mean that your machine will continue flawless with the exception of that circuit. Everything is eventually connected:-) Trying to find a decent image of that particular area so I can point the parts out individually.

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OT, the effort is genuinely appreciated and I look forward to seeing what you can find image-wise :)

I totally appreciate that its all connected, I just find it odd that the whole machine was 100% non-responsive (even when I attempted an emergency power-on by opening up and shorting two pads), but then suddenly came back to life. There have been no problems since, machine is fine! However I'd like to make sure it last another couple of years if possible

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Kyle, totally agree with "last another couple of years if possible ", that is why I appreciate ifixit and what it stands for. I bet it will be possible to nurture this machine along. It may take a bit of work, but not impossible. The parts I listed above are readily available and even traces can be fixed (even so not an easy task). BTW, welcome to ifixit :-) Again, I verified all the components being part of the audio circuitry, and I somehow bet it was Q6802 that started this issue.

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OT, you are a life saver! Can I ask what you mean by traces? I'm a fairly technical person by nature, but I'm no electrician. Haven't worked with circuits properly since taking Systems and Control at GCSE 10 years ago!

Thanks for the welcome, this is an awesome community... I have received great information within a couple of hours of my original post. This has not been possible anywhere else.

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Kyle Packer will be eternally grateful.
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