Not sure I understand your post:
never a good idea to remove the heat sink unless you really need to, especially with AMD CPUs.
With the AMD designs theres too much chance of the thermal paste acting like glue, and ripping the CPU out of the socket - possibly killing the board.
Intel designs aren't so much of a problem, though some motherboards object to having the heat sink twistlocks removed and reseated too many times
Why would the Mboard be killed with no power?
Like Tony I've built (asembled I mean) computers from the 486 up. They are just a poor mans meccano set.
Regards
Exeng