Well, I just got myself a Phenom II 550 BE and installed it today. It was working just fine until I restarted the computer. The Bios came up and then the computer turned off. The computer then went through a cycle of boots lasting for only 2 or 3 seconds each. So I put in my old cpu, phenom 9600, and it doesn't go into a boot cycle it just stays on with a blank screen.
So I'm wondering if anybody knows how to stop this cycle and which part malfunctioned: Did the motherboard short or was the cpu defective or both?
Can't wait for a response, I rely heavily on my computer to do school work and have resorted to using this old laptop.
Try reseting the bios by removing the battery from motherboard for a min with power unplugged also press power button to release any charge left in the PSU's caps. Replace battery put the new Phenom II in and see what happens post back.