I have a Penryn-Based MacBook Pro that I bought in February of 2008. It is a 15" 2.4GHz / 2GB / 200GB 5400RPM / 256MB Vram. Recently, I upgraded to Snow Leopard and the new battery information let me know that my battery was at low health and needing to be replaced soon, but I don't remember the exact percentage of my battery life. I don't think replacement was crucial. Yesterday, I took the MBP off the charger and let it sleep unplugged while I ran to do some work. When I returned home, the computer would not turn on but the blinking sleep light was flashing. I tried to charge it, but I had no success trying to turn the computer on. I Held the power button for a few seconds, and that shut down the computer where the sleep light was then completely off. Since then, I have not been able to get any response from the computer. The battery has a full 5-green lights on the back, and the power adapter lights a bright green when it is plugged in. I have tried taking the battery out and back in. I have tried holding the power button without the battery/adapter connected. I have tried just about anything. The computer just does not respond. Since this is a 2/2008 model, there is no warranty, and it is right in the middle of the semester.