I have removed the fan and heatsink and cleaned it all. I have also applied new thermal paste to the CPU but it still cuts off. I dont know how to check bootup. If I put the computer on its side and blow a fan set to cool into the cpu, the computer will run all day. If I keep the fan on when the comp is starting up and then remove it after startup, the laptop will run until I try to run a program when its fan will come on, speed up and the machine will shut down.
Have you found the problem.
I am working around the same problem and did the same with the external fan.
I am thinking of problem with powersupply of build in fan. I have unplugged build in fan during testing with external fan.
I did the same what 999thay did with external fan and unplugged build in fan. Laptop all day on with no shutdown.
I noticed also with startup during posts "1 AMD Northbridge rev unknown". What could be the problem???