I got an old HP Proliant ML350 G5 from work a while back and haven't found a use for it as it is too old. The only thing I had salvaged from it so far was the SAS disks that were still good.
I was about to throw it away now when I noticed that it did have a 1000W PSU with dual redundancy and that got me intrigued since I had been planning on getting a beefier PSU for my home server.
The problem is that HP doesn't like following standards so there is no way to connect it to my SuperMicro motherboard that actually follows the ATX standard pretty well.
Many hours later equipped with a multimeter and an Arduino that had to fill the role of a signal analyzer I think I have figured it out and since I found exactly two forum posts from people who had been trying to do the same, one four year old on reddit and one two months old here on LTT, I thought I should share my findings with anyone interested.
For those of you who are not familiar with HP Servers, here are some images.
PSU Backplane
Power supply, there are two of these connected to the backplane
P1 P2 P3 P10, P4-P9 are just standard molex connectors.
My test setup
P1, P2 and P10 are connected to the System Board
P3 is connected to the SAS Backplane
This is the pinout that I have been able to figure out:
P1
Orange
+12V3
3
Red/White
+12V4
3
Red
+5V
4
Black
Gnd
8
18
P2
Yellow/Blue
+12V1
3
Brown
+3.3V
6
White
+3.3VAUX
2
Purple
+5VAUX
1
Yellow
-12V
1
Black
GND
7
Yellow/Black
SB_RETURN
2
22
P3
Brown/White
+12V2
2
Brown
+3.3V
1
Red
+5V
2
Black
GND
5
10
P10
Purple
? (3.8V)
1
Brown
+3.3V
1
White/Green
+3.3V
1
Red
+5V
1
White
Data?
1
Yellow
Data?
1
Black
GND
7
Green
PS_ON
1
Pink
PS1_ON
1
Red/White
PS2_ON
1
Grey
PWR_OK1
1
Blue/White
PWR_OK2
1
18
To get everything working I am gonna have to replace the connectors with regular ATX ones according to the following
ATX 24 Pin
+3.3VDC from P2-Brown
COM from any GND
+5VDC from P1-Red
PWR_OK from P10-Grey+P10-Blue/White through an OR gate made up from two diodes and a resistor. I might end up doing something more fancy here so I can have some kind of warning if one of the PSUs fail.
+12V from P2-Yellow/Blue
-12V from P2-Yellow
PS_ON from P10-Green
+5VSB from P2-Purple
P10-Pink and P10-Red/White also need to be conncted to P2-Purple to tell the PSUs to start.
EPS1
+12V from P1-Orange
COM from any GND
EPS2
+12V from P1-Red/White
COM from any GND
No PCIe power since it's a server without a Graphics card.
Molex is already ok and will be converted to SATA power. They are drawing +12V from +12V2, the same as P3-Brown/White.
So the four +12V rails will be splitted up between
Motherboard
CPU1
CPU2
Disks
This seems to be what HP intended in the first place.
Now I only need to find a place to fit it all in my Corsair Obsidian 750D.
Hope you found this interesting.
ML350G5PSU-ATX.xlsx
