Chosen Solution
I posted previously in another post about my macbook that wouldn’t power up. I ordered a new logic board and installed it this afternoon. I was in the middle of installing snow leopard when the computer shut down. Long story short, I found the fan was dead. I replaced with one from another computer. I now can’t get 2 seconds past the apple logo. What could be the problem? I’ve tried starting with the battery out and with it in. Trying different ram from other computers I know are good. Nothing. UPDATE… I booted in safe mode. I got all the way to the login screen. The keyboard wouldn’t type, and the computer shut down. I had to hold the shift key down all the way to the login screen. Thanks in advance.
It sounds like the laptop is still overheating. Either the heat sink overheated and went bad or the board overheated and caused an issue with one of the BGA chips. Try cooling the board with some other sort of fan and see if it runs any longer. If this does not work you can try to preheat the chip. This is something that we do to determine if a BGA is bad. heat the chip up with a hair dryer or heat gun and do not go over 175C. In doing this you are trying to heat the connectors under the chip not the chip itself. You are also not trying to reflow the connections at this point this is just a test. Put it back together quickly and see if it stays on for longer. I would also cross your fingers that the heat sink is bad and not the logic board
answering everyone here. It shut down after the apple logo and the pinwheel spin. I got it in safe mode almost to the desktop, but as soon as I let the shift key go, it shut down. I couldn’t get it from the original disk. I don’t have it. The seller didn’t provide it.