resurrecting a fat PS3

found a Playstation 3 (model CECHH04) by the dumpster. cleaned it up and inspected - it's missing the BD and the HD and its cage; I jammed a normal 2.5" HDD in there and stuck some cardboard around. the light turned green, the HD spins up, the fans are spinning and the TV shows it's alive - no OS though.

I've downloaded Sony's official firmware and also some evilnat CFW jailbreak; tried both but the prompt on the TV is to attach a controller to the USB and press the PS button, which I haven't got. can I do something without it? tried a noname PC gamepad and keyboard but no go...