MacBook Logic Board Failure?

Hi all,

my MacBook is acting kinda strange. When the power button is pressed, 8 out of 10 times the screen remains black while the sleep light stays on. The other two times it will actually boot and go into the OS. I think I can hear the hard drive spinning and I've tried a different hard drive with the same result. So my question is: due to the fact that it sometimes still boots, is it definitively a logic board failure or could it be a loose connection somewhere? Even better, could it even be something other than a logic board failure, like a software issue?

This is a mid-2007 white MacBook running on a C2D.

Thanks a lot!

Before thinking about a hardware failure, try resetting the System Management Controller (SMC) on your MacBook. The SMC controls sleep - wake functions and some aspects of power on - power off.

See the following Apple KB article to learn how to reset. Link

Regards.

Thanks for your reply. I've tried that and that doesn't seem to help. Is there anything else I should try? Are the symptoms indicative of a logic board failure or does the fact that I still can boot sometimes speak against it?

Before condeming the logic board I'd try 2 things first. Either swap out the memory, or pull one chip and then the other as long as the remaining chip meets the minimum memory requirement for your Macbook. The other thing to do would be to try starting it from the charger without the metal 'L' bracket that covers the memory slots and hard drive, as sometimes this can short against the memory chips. I've never seen loose connectors causing your problem.

Thanks for your suggestion Steve. I've done all those things (more or less). I initially suspected it to be a RAM problem, so I put in a 1 GB stick from another laptop of mine that I know works. Well it didn't help solving the problem. I am constantly running off of the charger since I don't have a battery with this unit. Also, the L bracket is currently off but I am still having this problem. Hmm, any other suggestions? Is there a way I can run some sort of a diagnostic to test the logic board?

I tried booting off of the Leopard disk today - same thing: it goes into the installer for a while before it turns off, or it will take several tries before I can turn it on. In the cases it doesn't turn on I get a lit sleep light. Does anyone have an idea?

It is beginning to sound like maybe your logic board is acting up. Or, it could be the power control unit that's intermittent. If the machine is still under warranty or Apple care, take it on in and have one of the genius folks look at it. By the way, I wouldn't be running the machine with that "L" bracket off for very long, it's there for a reason.

Regards.

Sooo strange... now I just turn the computer off and on ten times in a row and it worked every time. I have gotten this to happen a few times in a row in the past few days, but never this many times. I really think it's just a loose connector somewhere rather than a bad logic board, but where? Hmm...

This exact thing is happening to my Macbook 13". Did you find out anything more about yours?

Try resetting the PRAM (hold down Cmd+Opt+P+R on startup). I'm not 100% sure what this does, but it's definitely a good thing to try and won't do any harm. Also, I'd try booting into Verbose (Cmd+V) or Single User (Cmd+S) and see if that sheds any light on your problem.

Same problem here. Anyone come up with a fix for this?

Same Issue, BUT Boots fine with no battery installed!

TRY: removing battery completely. connecting macbook / mbp to ac power (battery still removed).

Mine will work completely fine while the there is no battery and its connected to AC power....what does this mean?

(And yes, I have tried multiple batteries)

Maybe a bad DC input board? Check it out - go to iFixit: The free repair manual and look up your model and the step by step for changing that board. They might also sell the board if they have it in stock.