I have a Slot A Athlon 1GHz CPU that locks up whenever it enters protected mode. I've tested this with several operating systems and different software, and it's always the same spot every time.

I also have tried different CPUs, different RAM, and different motherboards and can conclusively rule out other source of the problem besides the CPU.

Has anyone else encountered this? I imagine this is some bizarre damage to the silicon but maybe there is something I am missing that I can try.

I thought about writing my own code to see if it's something after protected mode like a specific instruction but I am not sure what that would even get me or if it would be worth doing.