Released October 2008 / 2.4, 2.53, 2.66, 2.8 or 2.93 GHz Core 2 Duo Processor

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Starts with blank screen.. usually black, sometimes lit

This morning I woke my wife's Unibody MacBook Pro to find it warm with the fans running, a black screen and the sleep light on. Unable to wake it up, I powered down expecting to be able to recover it on restart.

This has happened a handful of times before, and up until now we've been able to restart and move on. However, today we are unable to resurrect this computer.

Most of the time the only thing I get on power-on is a black screen and a sleep light. No start-up chime or anything.

SOMEtimes I get a startup chime and a white screen, but nothing else... no "clueless Mac", no Apple logo, no pointer, nothing. Modifier keys (target disk mode, choose startup drive, recovery drive, etc) have no effect.

I've tried all the usual troubleshooting steps: reset SMC, reset NVRAM, reseat RAM, disconnect HD... no joy.

What am I missing? Is there any hope to recover this machine? I know the local Apple dealer will simply say "needs a new motherboard" without even looking at it, so that's not an option.

Any advice and/or help is appreciated.

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This is most likely an issue with C7771 on the logic board, on the 1.05V line required to startup. This tantalum capacitor commonly goes bad on the 2008 15" models, which can make it completely dead, turn off during usage, or not pass POST and chime.

If you have experience microsoldering, I can guide you on how to do this. If you have not got experience, I would recommend sending it to someone who is aware of this issue and have the tools/experience required :)

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Soldering, yes.

Microsoldering, no.

Sigh.

Is that something the local lazy dealer would call, "needs a new motherboard."?

Thank you for the reply.

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I'm afraid a lot of places do quote for a new motherboard (especially for these kind of issues, since they usually think it is related to the CPU).

If you are in the UK, feel free to send it in to us to repair. Otherwise, you might be able to do this repair with just a soldering iron, but it may be a bit fiddly.

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Thanks, but I'm in USA (Wisconsin). Is there a test that can confirm the failure of this particular capacitor? Don't have access to an o-scope, all I have is a small old multitester.

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Yes this can be checked. Grab a schematic and board view for your MacBook (board number on the logic board, think it is 820-2330), search in the board view program for C7771. Measure the side which isn't ground, whilst the charger is plugged in (and the logic board is not in the computer, since you will need to measure the capacitor on the bottom of the board). If it is not 1.05V (usually 0.3V), this cap is the issue

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Could be a couple of things. The white screen indicates a failed hard drive. Try disconnecting the drive and booting from the original system installation disk or an external boot drive.

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Booting from a known good thumb drive did not work. I pulled the hard drive, and it was recognized normally by another system.

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Thank you for the reply.

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obbie will be eternally grateful.
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