How about hitting the Cuda button the motherboard, also I had to switch on then off then on again the first boot even after hitting he switch. Again I don't know why I tried it or why it worked. But it worked on three G3 desktops that would not do anything after people tried to load OS X on them. I know yours is an 040 but just trying to say forced video and something (maybe in rom) gets sideswiped by the video (only just guessing and shooting in the dark).

Again best of luck