Indigo power supply pinout

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sadness
Posts: 23
Joined: Tue May 18, 2004 11:49 am
Location: Rome, Italy
Contact:

Indigo power supply pinout

Unread postby sadness » Fri Oct 15, 2004 8:57 am

i'm trying to resurrect an old control data cyber 910-200
(sgi indigo) which was aquired as broken (do not power on)
(and after the italian postal service treatment is _really_ broken,
see photos of the smashed poor little indigo at http://www.unsupported.info/smashed_indigo/)

i need the power supply connector pinout, i'm thinking of
using a standard atx power supply to power on and test
the machine

thanks

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Intel-OUTSIDE
Posts: 1092
Joined: Tue Dec 16, 2003 6:45 am
Location: EU

Unread postby Intel-OUTSIDE » Fri Oct 15, 2004 10:37 am

make sure you know the voltages supplied by the old psu, i think they are different from atx.

i have never seen the data you want, but there was a website with data in challenge-s psu,

here is a past:



I bought a used Challenge S machine, which turned out to have a broken power
supply. I was told the replacement part was expensive and possibly complex to
get, so I set about either fixing or replacing it.

A friend of mine familiar with electronics spent a few hours trying to find the
problem, but failed (it was not one of the common problems Google turned up in
response to a query about Indy power supplies).

So, here's the information acquired by mailing Nidec / Power General (the
manufacturers of the original Indy power supply) and reading a web page from Net
Express. Please note that while Nidec / Power General were very helpful in
providing me all the information necessary, they no longer manufacture these
supplies.

The smaller connector for the SGI runs mainly between the control panel and the
mainboard. Only three wires go to the power supply itself, and of those none
exactly match the ATX signals. I'll cover them later. The next table is about
the larger connector, which is of the same type as the ATX connector.

Color codes for matching leads

ATX color ATX pins Function SGI color SGI pins
Orange 1, 2, 11 +3.3V White 1, 2
Black 3, 5, 7, 13, 15-17 Ground Black 11-16, 18-20
Red 4, 6, 19, 20 +5V Red 3-8
Purple 9 +5V aux (always on) Green 9
Yellow 10 +12V Yellow 17
Blue 12 -12V Blue 10

Other leads

The connections above can power your SGI, but will not start it. The remaining
ATX signals are Power On (Green, pin 14), Power OK (Gray, pin 8) and -5V (White,
pin 18). The remaining three SGI signals are all on the second, smaller
connector; I suggest cutting these leads close to the power supply itself. They
are Logic Inhibit (White/Red, pin 9), Fan Control (Brown, pin 20), and Power
Fail (Orange, pin 19). -5V is simply not used in the SGI.

One might think that Power Fail and Power OK are similar, but in fact they
operate at opposite ends in time. Power OK is used by PC power supplies to
indicate that enough voltage is present for operation; the SGI assumes this to
be the case when power is activated. Therefore, my Challenge S always fails two
tests in the POST when it gets powered on. Power Fail is used as a 5 ms UPS
function; it goes low at most 5 ms after power is lost, and at least 5 ms before
the main +5V supply drops to +4.75V.

Fan Control is a three-level control for the speed of the fan. At 0V, the fan
spins at low speed; at 3.3V, it should operate at medium speed; and at 5V, it
should run at full speed. I connected the fan directly to a floppy connector (it
needs 12V) so it always runs at full speed.

Logic Inhibit does the same thing as Power On. However, you'll need an inverter
(powered by 5V aux) to get it to work. While I hadn't soldered mine in yet, I
connected Power On (Green from the atx supply) to ground (Black) to start it up.
Now I use a 4049 inverter, connected to ground, +5v aux, logic inhibit and power
on. Remember to connect all inputs to something - they should not be left
floating.


--------------------------------

if your old psu wont start then change the small electrolytic capacitors. :)

sadness
Posts: 23
Joined: Tue May 18, 2004 11:49 am
Location: Rome, Italy
Contact:

Unread postby sadness » Fri Oct 15, 2004 8:04 pm

Intel-OUTSIDE wrote:make sure you know the voltages supplied by the old psu, i think they are different from atx.

i have never seen the data you want, but there was a website with data in challenge-s psu,

here is a past:
....

if your old psu wont start then change the small electrolytic capacitors. :)


oh i know the page with the challenge-s/indy atx power supply rewiring,
i have done this years ago for a friend's indy (that is currently in use
with the atx supply mounted in the original power supply enclosure)
(was the first sgi in my hands :) )

however i'm not searching the pinout anymore, just repaired the old
psu, a shorted bridge rectifier in the primary section of the psu and two
missing fuse (and some sign of a previus reparation attempt), there
some weak electrolytic capacitors but the psu is happy (i will replace
later, maybe this night)

now the machine in up & running over serial console, need to make
an indigo - ps2 adapter one of these days, now it's time to search for
an r4k indigo mb, r4k4 150Mhz pm2 cpu and an elan :) (and to send a
formal complain to the italian postal service for the damage)


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