I have a 2010 macbook pro 15 inch icore 7. I bought it used and it was running with only one stick of 2g ram. I bought 2 sticks of 4g ram for it but it wont start when they are installed. I currently have 3 macbooks and interchanged all the ram sticks between the different macs to make sure the ram was good and it is. No combination of ram over 2g will work. I've tried 2x4gs, 1x4g, 2x2gs all with the same result. The sleep indicator light will come on when I try to turn it on, just a steady light, and the screen stays black. No chime, none of the keyboard commands do anything like holding shift or option ect. If I take all the ram out it gives me the three beeps to indicate no ram. I have a few times got the macbook to start with the full 8g of ram after reseting smc but its very very rare that it works, and when it does the macbook usually freezes right after login. I can put just the single stick of 2g ram into either slot and it runs perfectly with no issues. Does anyone have any idea why more than 2g of ram would cause these issues? I'm usually pretty good at tracking down a solution but this has me completely stumped. Only thing I can think of is a failing logic board but I have never heard of one failing only with more than 2g of ram. Help?