Try re-seating your RAM and see if that helps. I had the same symptom (front light on and nothing else) when I first upgraded my RAM. The problem went away when I re-seated the RAM.
I actually had my logic board fail on my C2D Mini about 10 months after I purchased it and when that happened, nothing would come on. No lights...nothing! I was hoping it was just the power brick, but it ended up being the logic board.