Hi I have searched this forum before posting but still no solution to what I'm having. My MacBook Pro A1278 was working great until I powered off. On powering back on, I got a flashing folder with question sign. Now that, I thought, was caused by a faulty hard drive. I've changed the hdd but same issue. I purchased a new 10.6.3 installation disc from the Apple Store hoping to boot from it. So what is going on? Pressed power button, insert disk then restart. Powered back on the fan starts to spin fast then it goes to the apple logo and sits there. I removed hdd, held "c" I got same loud fan and it boots to the apple logo (from installation disc). I have done SMC reset and PRAM reset does not work at all. Do I have a "RIP" logic board? I have no warranty. Regards.