SGI Indigo Power Supply Pinout?

ethan at ethan at
Sat Apr 7 23:18:37 CDT 2018


  Working on fixing an old SGI Indigo of mine in prep for VCF East.

  The issue is once any sort of IRIX kernel is running, it craps out 
WARNING: Power Failure Detected at a high rate.

  The SGI Indigo and a few other similar models could push out 
that error on the local console and perhaps network inbetween the time 
that AC power was lost going into the power supply and the power supply 
had discharged enough for system to die. Pretty impressive and strange! 
I was amazed when I first noticed it, of course now it has come back to 
haunt me.

  I have replaced some of the electrolytic caps in the power supply.

  But in the spirit of troubleshooting, does anyone have any sort of 
schematics or documentation on the power supply, or the midplane?

  This is a R4000 Indigo and has the higher output power supply to support 
bigger CPU and graphics.

  In the meantime I'm working to document what I can about the power 
connector and will publish, but I can only get so far without other 


: Ethan O'Toole

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