I have a 2011 Macbook White. I am guessing its 2011 not sure. This computer did not cost any thing so I am not to worried if I cannot be helped here. Here is the problem: Problem: Sometimes the computer will not come on. The screen will flash but nothing happens. I have been able to get it to come on holding down the power button for 10 seconds releasing it plugging the MagSafe back in, holding the power button for another 10 seconds then pressing the power button and it starts up....It has a 60 Watt MagSafe...And is running Snow Leopard..... It will come on and stay on but I have to keep doing the above. Any help or ideas appreciated. Note: Does anyone know if this computer will run Mountain Lion?