Mid 2006 / model number A1181 / black or white case / 1.83 or 2.0 GHz Intel Core Duo processor.

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Fixing logic board? LED lights up steadily, Fans turn, no chime.

Hi there,

my sisters Mac Book just died while in normal use, running cool with no tell-tale signs in beforehand. No mechanical abuse or liquid damage occured.


- MacBook Core Duo, Late 2006, black

- 2 GHz

- 2x512 Meg RAM

- Three-Walled connectors

Symptoms after pressing the power button:

- Fan spins

- Display flashes shortly as usual. Stays black

- No chime sounds. Ever.

- When RAM is installed, LED turns on and stays on.

- When all RAM is removed LED flashes rapidly.

- Swapping RAM/Reseating and using known working RAM does not change the Situation

- Shuts down after holding down the power button for a longer period. Does not power down by itself.

Things I did:

- Removed the board, cleaned with professional PCB cleaner fluid (Kontaktchemie LR)

- Removed the SRAM-Battery for a few minutes

- Tried booting with and without HDD, Airport-Module, Battery

- Symptoms change slightly when removing RAM altogether (see above)

- Mechanical an electrical inspection done, no visible damage or signs of severe corrosion.

- All fuses I was _able to find_ seem ok.

- No signs of liquids or scorches

So basically I'm running out of ideas how to "simply fit it". I'm an electrical engineer and am able to fix complex things with a schematic. Having worked a lot with SOT323, BGA, 0402 SMD and all it should be doable, but without a schematic I'm screwed.

Maybe someone could give me a hint towards a schematic. If I get it working I will keep you informed for others who might to come this way, too.

Thank you in advance!


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2 Answers

Chosen Solution

Please check my answer here:

Why is it that my MacBook doesn´t start?

A faulty logic board, a bad internal component or cable can prevent the machine to power and boot the system so disconnecting everything you can and then try to power directly the logic board (without the top case attached) is a good way to troubleshoot the machine. If you get the same results then it's probably a faulty main board and it's pretty hard to find Apple products schematics. They don't want you to repair your machine or shops to repair their logic boards. They prefer that you buy a new machine...

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Most Helpful Answer

I've sen this machine do exactly as described with a failed hard drive. Try removing it and see if it will boot from the optical drive.

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Thank you for this hint. Unfortunately it didn't help. As I wrote I tried removing everything except for the Power connector and the Top case.

There is a "PWN BTN" in the white silkscreen print. Do you know which pads are meant to be connected? This way I could boot it without topcase..


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pt0799 will be eternally grateful.
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