Model A1297 Unibody: Early 2009, Mid 2009, Mid 2010 & Late 2011

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Why doesn't my MacBook Pro turn on?

Hi! My MacBook doesn't turn on. It's been taken to maintenance which stated that there could be a problem with the logic board.

After pressing shift-ctrl-alt-power and then releasing, the charger light turns green for a brief moment and returns back to orange. This happens every time.

Is there something to be presumed about the problem by this particular symptom? Could there be another solution than to replace the logic board?

Thank you!

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Will likely be C7771 on the logic board causing the problem if it is the older 2009/2010 model. Get a schematic and board view for your particular model, and measure the voltage on this component with a multimeter. If you are getting around 0.3v, replace it, and it should fix your issue.

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Where would you get a schematic? What is the C7771?

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Just Google the board number, and add schematic after it. There are a number of websites that sell these.

On board view software, search for C7771 to find it's location in relation to the logic board. Measure it, and if it is 0.3v it will need replacing, since it should be 1.05v from memory. This capacitor commonly fails on the older models, pulling the voltage for this power rail down.

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Update: after replacing the 330uF, 2V poly-tant capacitor in B2 casing in position C7771, and after charging the machine indeed started.

The component is very small and was difficult to solder in its place so I wouldn't recommend performing this yourself without proper tools and experience in similar work. I followed this guide when taking the machine apart: MacBook Pro 17" Unibody Logic Board Replacement

A picture of the logic board with the C7771 highlighted can be found on the internet somewhere. I found that useful, too.

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