Re: Overheating CPU causing problems
The motherboard reads the CPU type and automatically sets the voltage correctly for the type of CPU. You can't set it yourself, because doing so would be more likely to cause problems than fix them. If you can run it for long enough you should be able to go into the BIOS and check that the voltage is set correctly, which is 1.65V. If its not 1.65V then its possible there's motherboard problem, but its more probable you've got a faulty CPU.
The problem is almost certainly not the motherboard but the CPU cooler. Either it is faulty, or it is incorrectly installed. That model CPU cooler is a good product, well able to do the job of cooling an Athlon XP 3000, but it is a complex high-end product with a complicated installation process. It has a temperature sensor that has to be installed correctly, and a speed controller that has to be set correctly and which only works if the temperature sensor is installed correctly.
If the voltage is right and the CPU cooler is definitely installed and working correctly then it back to being a CPU problem. Wherever you got your "new" CPU its faulty.
(As it happens I'm typing this on a PC that uses a motherboard of that type that's running an Athlon XP 3200 with a smaller CPU cooler than that, a Thermaltake 10+ that only runs a 60 mm fan, and, yes, it runs a bit hot on a hot day - about 25C above ambient temperature - but they're able to cope with up to 85C.)
