OK, I tried it earlier with my old AMD kit. I did make a crappy film on my phone but to be honest there's not much to see.
The board only supports IDE and I have no IDE HDDs or optical drives so I couldn't boot into an OS to test. From the BIOS all that happens is the temp starts to rise as you take off the heatsink and then as you remove the CPU it hangs. Fans still spin, lights stay on but nothing happens until you kill the power. CPU and mobo worked fine afterwards.
The board only supports IDE and I have no IDE HDDs or optical drives so I couldn't boot into an OS to test. From the BIOS all that happens is the temp starts to rise as you take off the heatsink and then as you remove the CPU it hangs. Fans still spin, lights stay on but nothing happens until you kill the power. CPU and mobo worked fine afterwards.