sseay, I've discovered that you have to hit that key repeatedly. Follow these guidelines:
1) First, unplug the unit from the wall. This won't work if it's just in a regular shut-down state with instant-on Virginconnect screen. So... unplug the unit from the wall for a full power-down for a few seconds.
2) Then plug the unit back in. You'll see that you don't even have to press the "on" button now because it will turn on automatically once it's been unplugged and plugged back in.
3) Immediately press that "open-book" key repeatedly until you see the BIOS screen. (The "open-book" key corresponds to F2 on a regular keyboard.)