[weblacky]

I forgot to mention I tried 3 different keyboards, one of which was SGI, and all 3 work on other Indigo2s.

I have the serial console attached but never see a prompt when its booting. Even if I get into the prom or an OS, I don't know what that will tell me. I know the keyboard layout is correct because I can check that with the mouse, which does work on the second keyboard daughtercard.

Tomorrow I'm going to swap back to the spare motherboard and see what happens with both daughtercards.
I just cant imagine what components would fail on that relatively simple board.

Ah, well that changes things doesn't it.  I've not seen symptoms like this before...I'll give it a hard think.  Keep us informed of your progress.