amd burn out

help! i have burned 3 amd processors already in my new system!

installation of processor #1 (amdxp 2200+):
a thin layer of thermal grease was applied. heatsink was installed. processor was installed perfectly and ran well until i shut the system down, removed then replaced with the same heatsink fan. system would not boot afterwards and processor burned out.

installation of processor #2 (amdxp 2200+):
a thin layer of thermal grease was applied. heatsink was installed. system did not boot at all. processor burned out within seconds.

installation of processor#3 (amdxp 2400+):
took system to store to have installed by A+ certified technician. system booted for a minute (said the technician). processor burned out seconds later.

mobo: soyo sy-kt333 dragon ultra (platinum ed.)
heatsink: thermaltake volcano 9 running @ max rpm
psu: antec pp-403x 400 watt w/ smart fan feature

might this be a motherboard problem?

if anyone could supply any help whatsoever, it would be greatly appreciated. thanks.

 

Is this a new motherboard? If so, I would definitely get a replacement.

Very unlikely that both you and the technician installed the cpus incorrectly.

 

yes, JSanguancheu, it's a brand new motherboard. in your, or anyone's experience, is it a common occurance where a faulty motherboard will burn out a cpu? or might my problem lie within my psu? thanks for your input! i've asked around and around and no one can seem to find the problem. i know that it may be difficult to diagnose a problem like this without having physical access to the system, but if i could narrow down the suspect components through anyone else's experience with this same problem it would be a great help. any alternate suggestions?