First off, dual channel is gonna be A1+B1 for the blue and A2+B2 for the white (these are the higher rated slots for DDR1200). Can you get it to boot as in either A/B 1's or 2's slots?
I do recall some mobos being tricky with new RAM and just after a BIOS flash. I would try reset CMOS and boot. If it POST, load system defults and go from there. Although I never had this issue with my ASUS. But worth a shot.
Good luck.
Bookmarks