i've never known what lights go on for what reason, however, i do know for sure that they light up if a power cable is not plugged in or if the computer isn't gonna POST.

also, don't bottom out the screws around the perimeter of the card, just the 8 that are around each GPU. if you bottom out the others, the card becomes warped like a mofo even though it has stand-offs.

if it still doesn't work, try to remount the stock heatsink and fan. if it works with the stock heatsink and fan, i would bet something is shorting out when the XSPC block is installed, not a thermal issue.