[SGIArtist]

Thanks for your reply. No, I didn't pull out the PSU every time, since I understood that unpluggng would be enough. I tried the power on jumper trick, but the machine still just boots without vga output so, I can't get to the console.

It just feels to me like the system board isn't making a good connection, but as far as I can tell it's not possible to push the board any further into the machine.