I'm having an issue getting a P6N SLI to post. I am currently testing outside of the case with only CPU & FAN, 1 stick on RAM, and video.
The issue is that if the 8-pin CPU power is connected the board will not power up (tried the 4-pin also just as a test). If nothing is connected to JPW1 the board will power up, the CPU fan will spin and the PSU fan will spin.
More aboutpower issue
I also tried a different PSU with the same results.