MacBook Pro will not start up....

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Here is an article that might help:

http://support.apple.com/kb/TS1365

Good luck!

I had a similar problem and I had to change the logic board.

Everytime I turned off or put it to sleep at night, the next morning it would not turn on or wake. No matter if the magsafe was plugged in(green or ambar light) or not. The battery was always full(I could see the eight green dots). When I pushed the power button I could see the white light in front of the MacBook blinking only once. A noise from the HD would start for a second and stop.

What I figured out was that I had unplug the magsafe and keep pushing the power button rapidly and constantly until making the HD to work. Usually took like one or two minutes to make it work and once it started it would run normally. I could turn it off or put it to sleep and wait for few minutes and turn it on again or wake from sleep without a problem.

_The problem was that I could not let my Macbook turned off or sleeping for a long time (overnight more than 6-7 hours)._


It seems to me that some component of the logic board could not work if it was cold (ambient temperature). That's why I had to keep pushing the power button to make some "heat". Probably a half broken circuit line.

I sent my MacBook Pro to service center three times until they finally decided to replace the logic board.

Now it works perfectly !

I, too, ran into exactly the same problem, though it did not ever start up. The usual fan and hard drive noises can be heard. I'm not absolutely sure if it is, the logic board that's causing the issue, and I need to know if Apple is still repairing these units for free. I reset the PRAM and NVRAM, and also reset the SMC. I have not tried removing RAM, but all the ram inside is the original factory-issued RAM (I think). If I hold down Control-Command or Control-Option while pressing the power button (whichever it is that forces a restart), the sleep indicator light flashes very fast for about 3 seconds, then remains steady. If I start up normally, the light remains steady. I cannot boot up off of an external HD. It will not work in Target HD mode or in Safe Boot mode. Please help! Thanks in advance,

Ahanu

Just to add some more details, the startup sound goes on about every 4th time I start up, and about every 3rd time, when force it to shut down, I hear the "Pew" or "Kew" sound the computer makes when you force it off. (Is that the HD, just for reference?)

Finally, the keys I pressed to get the weird sleep light flashes were "Control-Option-PowerButton".

Thanks for your help,
Ahanu

I'm also having the same problems, my start-up light is on when switched on but nothing happens. no noise, no HD, no grey screen etc.

Tired some of the tests from above, but can't reset the PRAM as it won't boot to the chime.

Is this a logic board failure?

There are many possible reasons for a failure to start up. Read the article that S.U. has linked above.

OK, well i've tried all the steps in that post bar the booking the genius bar appointment, so i guess that's my next port of call.

cheers