View source for Indy Power Supply Information

This page serves to document the SGI Indy PSU in detail. This article relies heavily on information from SGUG forum user "Elf" who made a post in 2019 about this. Unfortunately, Elf later chose to remove his work. Raion, the author of this version, has done his best to recreate the necessary bits, here, while respecting Elf's wishes.

== Physical Specifications ==
TThe Indy power supply is a hefty unit weighing in at just under 2kg on average. 
{| class="wikitable"
! colspan="3" |System Dimensions
|-
|Length
|Height
|Width 
|-
|34 cm
|7.5cm
|10cm
|}
The unit takes a standard NEMA C13 power input and has a Molex Mini-Fit Jr. 20-pin header for primary power, with auxiliary functions on a 2x10 0.1in spacing pin connector. 

== Electrical Specifications ==
The power supply consumes 170W at 100-240V two-phase mains AC voltage (50 and 60hz compatible). 
{| class="wikitable"
! colspan="2" |Voltage Rail Ratings
|-
| +3.3V
|7A
|-
| +5V
|25A
|-
| +5V standby
|0.02A
|-
| +12V
|4.5A
|-
| -12V
|0.75A
|}

=== Pinouts ===
[[File:Indy 20-Pin Connector.png|thumb|20-pin main connnector, referenced for "Main Pinout" Table]]
Power is supplied on a 20-pin Molex Mini-Fit Jr. type connector, with the motherboard side being the male connector and the power supply side being female. The pin numbers are as per the mechanical drawing. The +5V standby is supplied when the power supply is connected to AC line power but has main power turned off. The purpose of it is to power on the PSU. 
{| class="wikitable"
! colspan="3" |Main Pinout
|-
!Pin #
!Wire Color
!Function
|-
|1
|White
| +3.3V
|-
|2
|White
| +3.3V
|-
|3
|Red
| +5V
|-
|4
|Red
| +5V
|-
|5
|Red
| +5V
|-
|6
|Red
| +5V
|-
|7
|Red
| +5V
|-
|8
|Red
| +5V
|-
|9
|Green
| +5V Standby
|-
|10
|Light Blue
| -12V
|-
|11
|Black
|0V
|-
|12
|Black
|0V
|-
|13
|Black
|0V
|-
|14
|Black
|0V
|-
|15
|Black
|0V
|-
|16
|Black
|0V
|-
|17
|Yellow
| +12V
|-
|18
|Black
|0V
|-
|19
|Black
|0V
|-
|20
|Black
|0V
|}
Auxiliary connections are supplied on a 20 position 0.1" spacing (2x10) pin header, with the motherboard side being male and the power supply side being female. Noting the position of the connector key, pin numbering on these connectors alternates between the bottom and top row, starting from the bottom left.

The power supply is controlled by pin 3 (Run), which is "ground to stop." It naturally floats at +5V (standby), meaning that disconnected from the motherboard, the power supply runs and supplies regular power. The motherboard grounds out this pin to stop the power supply.
[[File:Pin Header Indy.png|left|thumb|Pin header drawing for SGI Indy ]]
{| class="wikitable"
! colspan="3" |Pin Header Pinout for Indy
|-
!Pin #
!Wire Color
!Function
|-
|1
|
|N/C
|-
|2
|Brown
|Temperature Sensor Control Voltage (0-5V)
|-
|3
|Red / White
|Run (Ground to stop)
|-
|4
|Orange
|Power good signal
|-
|5
|
|N/C
|-
|6
|
|N/C
|-
|7
|
|N/C
|-
|8
|
|N/C
|-
|9
|Gray
|Power switch (other leg to Switch Common)
|-
|10
|White
|Volume Up switch (other leg to Switch Common)
|-
|11
|Blue / White
|Volume Down switch (other leg to Switch Common)
|-
|12
|Periwinkle
|Reset switch (other leg to Switch Common)
|-
|13
|Black
|Switch Common
|-
|14
|Red
|LED Common (Anode)
|-
|15
|Violet
|Red Status LED (Cathode)
|-
|16
|Violet / White
|Green Status LED (Cathode)
|-
|17
|Orange / White
|Speaker (terminal 1)
|-
|18
|Green / White
|Speaker (terminal 2)
|-
|19
|
|N/C
|-
|20
|
|N/C
|}