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My computer was liquid damaged 6 months ago, and on service, they told me that the logic board had to be replaced. I didn’t do it, and bought a new one. a couple of weeks ago, I tried to power on the old macbook, and it went on. the only problem was that when in os, it was like I pushed the power button, and the power off window in os pops up. If I don´t do anything, the machine just turns off, and I have to restart it. but after about 8 starts, it suddenly won´t turn on. I talked to a technician at an apple workshop, and he told me it could be the power swith and told me that i should try to start it up by short curcuit two pins on the logic board. does anyone know where they are located? He tried to explain it to me, but it wasn´t easy, since I didn´t have the machine with me. Picture would be nice. Update Thanks for the advise. this is the same problem, but my logic board is newer than the LB in the post, so the location of the pins is different.
You will find the two pins near the touch pad connector. On the mid 2009 MBP they are almost hidden under neath the connector. On the 2010 they are out in the open. If you have a voltmeter you can ID them by confirming 3V on the one and 0V on the other. They are square in shape. marked photo of mid 2009 logic board
Look at this similar problem. You will need to examine the logic board if the location is different, but the marking will be similar. Remember to return and mark accepted the answer that best solves your problem. Good luck, N