Indy Power Supply Information

From TechPubs Wiki

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.

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).

Voltage Rail Ratings
+3.3V 7A
+5V 25A
+5V standby 0.02A
+12V 4.5A
-12V 0.75A

Pinouts

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.

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.

Pin header drawing for SGI Indy
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