I'm sure the PCIe slot power makes a difference, but the RS2WC040 requires an available x8 or x16 PCI-Express* slot. Are you using a x8 or x16 PCIe slot?
I see you've updated the RAID controller firmware, but have you updated the BIOS and associated firmware for the Asus server motherboard?
The correct answer is that you: Hit Control G and nothing seems to happen.
However you NOW go into your new style bios and click on "boot choices" or something like that.
There will be a fresh boot choice with a bizarre name. Click that and you are into the raid controller screen.
( You can appreciate that if you do NOT first hit Control G then of course there is no new entry in the boot choices menu in your bios. I did not realize that as I always gave Control G a try before going into bios to manually hit the new entry. ).
Piece of Cake once you know by trial and error.