The PPC chip is way too sensitive. Slight pressure could damage it. I'm serious! You have to treat this card like an egg.
A lot of people received CSPPC cards brand new from Phase 5 and DCE and reported them being DOA simply due to clumsy installations, such as pressing down on the heatsink to make the board secure in the CPU fast slot. Of course, no one was told to watch out for this so the users didn't know. When you install the card you actually are tempted to do it in order to easily fit it in, as it is a perfect pressure point, but you shouldnt...
This was not always true for defective cards, as also indeed a lot were simply dead on arrival, such as DCE made batches.
A lot of cards had bad cooling fans over the PPC heatsink which either didn't provide enough cooling or they simply died after a few weeks of usage and afterwards the PPC chip overheated constantly and killed the card. This is hard to notice as most of us keep our desktop cases closed and cannot directly spot a non-functioning fan.