About a year ago i purchased a 1.33ghz amd thunderbird proccessor for about $300 canadian, i was all ready to go with my alpha heatsink, silver thermal paste, etc etc. This was my first athlon procesor i ever installed. First go, i cracked it, smelled like burnt silicon. win2k started booting, bsod, crashed, never posted again. actually had burn marks on the heatsink, and ther was a nice dent in the heatsink. so lost a heatsink and a proc on that one. i replaced that processor with a 1.4 athlon about 2 weeks later (another $300 canadian, + 60 for the new alpha heatsink). that went in without a hitch, then about 8 months later after running it at 1.4ghz, i decided i needed to try the pencil trick (because im an overclocker). did this, and put on a different alpha heatsink this time which allowed me to mount a non-thin fan. (7000 rpm delta). Putting it on this time, the computer posted, and then died shortly after.. same burnt silicon smell, same chunk taken out of the heatsink. I replaced it with a 950mhz athlon from a friend ($60 canadian this time) which is humming along happily at 1ghz, but i've lost quite a lot of cash in the past year on cracked cores! gonna be trying the pencil trick again on this processor, and im never using another alpha heatsink that uses the same clip mechanisim on the pal-66, this i think is what really caused the cracked cores.
(on the upside, i now brag about having a 1.4ghz keychain)