I was putting on a new heatsink/fan on my 1.2ghz T-bird, slapped everything together, fired it up.. and NOTHING! ACK! What did I do.. pulled everything apart, noticed I forgot to put the copper spacer in, and chipped a piece of the core off! Ack, I thought for sure it was dead.. Put everything back together carefully this time, and thank god it fired up.. How bad is a chipped core? I suppose if it works who cares.. Whew.. close call.. Heatsinks should really not require the amount of force to hold them in place that they do.. argh..