I've lost count of the times I found no heat sink compound, the fan not running and the machine in a "box" with little airflow.
There are also other issues such as the wrong BIOS or such. Given the issues I've encountered over the years I rarely find it to be the bad heatsink.
As to your question, if I wanted a copper heatsink and it needed a little millwork I'd use the usual black sharpie to mark what I want gone then off to the dungeon to mill it to my liking.
I recently bought a Jetway NC9B-HM67 Motherboard and tested it using Prime95's test for CPU temperature. Within 5 minutes running on a single core, cpu temp was at 100 C and was throttling the clock speed to keep the temp from increasing anymore.
I think the problems I am experiencing are due to the crappy aluminum heat sink the motherboard shipped with which unfortunately is a custom heat sink for a G2 socket since there are capacitors that surround the cpu and prevent it from using a standard G2 heat sink.
Has anyone found a copper heat sink that is compatible with this motherboard?