Hi Folks, This is a question for the board repair professionals. I've recently picked up a MacBook Pro (17-inch Mid 2009) MacBookPro5,2 for nil with some power issues. I tossed it into a cupboard and haven't touched it, but now I have some time to throw at it, I decided to see what I could find out. That and I've seen a few other MacBook Pros of the same size and year come through with exactly the same issue, so now I'm curious. The issue is simple. Press the power button, light comes on, and then it turns off. Often before the boot chime. Sometimes it will make it past the boot chime, then turn off. Sometimes it will make it to the grey Apple logo and then click - off it goes. The LED on the front turns off suddenly. Then, maybe after 10-12 tries, it starts, and runs, and it doesn't turn off. If I attempt to start it purely from battery, there's no chance of starting it. The power adapter has to be connected to even have a shot. But even with the battery disconnected and running purely from the power adapter, it still does the same thing. Removing power consuming devices from the system, such as disconnecting the hard drive, also allows the machine to start a little more easily, but it still turns off about half the time. Performed a component isolation, stripped back to a Logic Board, different RAM, different components, different fans, heatsink mounted correctly, new thermal paste, not getting hot - and the issue still occurs. It's somewhere on the Logic Board that it's failing. This we know for sure, so thanks in advance for the suggestions of taking it into Apple, but the Genius Bar won't help me here. This machine and board has never been exposed to liquid, machine has never been dropped. I thought it was isolated to this machine, but as I said, I've seen a couple more since then with the same symptoms, same year, same model. I believe the Logic Board is an 820-2610-A but admittedly I'm working from a somewhat hazy memory. Has anyone seen this issue before and was able to isolate it to a particular common component or failure point? I don't mind probing around with a multimeter but the guidance would be appreciated. The age of the machine is no concern, this isn't mission critical, but mainly for the experience. A working machine at the end wouldn't be bad either, I suppose. Cheers, ~ iMic.