# Converting a DPS800 server PSU into a standalone 12V PSU

I recently got my hands on 2 server PSUs from a HP Proliant DL380-G5.
HP model DPS-800GB A REV 06M Series HSTNS-PD05
Partno: 379123-001 (They appear to be made by Delta, going from the logo on the internal PCB.)

These can output a whopping 82A max at 12V (with 240V input), which would be very nice to power some LIPO battery chargers.

I know it is possible with the closely related DPS-700 and DPS-750 PSUs that use a very similar internal PCB.

Does anyone know how to convert/modify these DPS-800 units to function as standalone 12V power-supplies ?

• So you say they can already output 82A at 12V, what exactly do you want to modify? – PlasmaHH Aug 20 '15 at 14:48
• It doesn't work as is. It expects control-circuits to be present on the motherboard, like any other computers PSU. In this case even some circuitry that provides the hot-swap/redundancy logic as these units are always used as redundant pairs in a server. Usually you need to wire some pins together with one or more resistors in between to fake the control logic. Question is: Which pins, How ? – Tonny Aug 20 '15 at 14:54
• Pinouts for these power supplies aren't usually provided by the manufacturer because it's not needed unless you're trying to hack it to do something other than power your server rack (which is not something they want you doing.) If it's a common-enough supply, though, it's likely somebody's poked around and hacked something together. See this offsite thread for a supply that should either be yours or one much like it. – Cheibriados Aug 20 '15 at 15:15
• I have a couple DPS-1200FB A (12V/100A) which I managed to turn on by shorting two pads on the output connector. If you upload more information and an image, I can check if the connectors look similar. – jippie Aug 20 '15 at 15:35
• @Cheibriados I know that site, but somehow didn't manage to find that thread. It's exactly the info I need. Make it an answer and I'll accept it. – Tonny Aug 20 '15 at 20:17

Your PSU seems to be a common one and the necessary pins were determined by members of an external forum devoted to radio control enthusiasts found here. The solution seems to have been discovered by trial and error, and the poster claims that shorting pins 31 and 34 (which should be labelled) allows 12V to flow to the rail.

Server power supplies don't tend to have typical connectors like PC power supplies do, but instead have some sort of interconnect system consisting of pins or exposed pads like those seen below (with the resistor and solder omitted, naturally.

Most of the interconnect is taken up by those two large pads on the right which can generally assumed to be 12V and Ground given that the job of PSUs is generally to deliver 12V to the server rack at high current. That doesn't leave many pins left to test and process of elimination can narrow the choice of which pins you should test.

One member of an RC forum compiled a short guide on determining which pins to short if you're going in blind given some assumptions about how the supply works and what it expects. Since these PSUs usually short the DC ground to the chassis ground, all of the ground pins can be determined using a DMM and eliminated. From there, the voltage on the rest of the pins can be referenced to ground and the number of pins to test is decreased substantially. Shorting one or more of those pins to ground through a resistor should likely result in the PSU turning on.

Note that this assumes that the power supply in question requires a simple active-low/high logic voltage to turn on. More complicated supplies or supplies requiring some other control signal will likely not work in this fashion.

• I found that on the DPS-750RB A that a 600ohm resistor between pin 33 and 36 did not work, whereas a 0 ohm resistor between those pins does work. – spuder Apr 1 '17 at 5:02

While experimenting a satisfactory solution was found. (1) Connect track 31 with 34 (to boot) (2) Install a resistor between track 32 and ground see http://pa0fri.home.xs4all.nl/Diversen/DPS-800GB%20A%20Server%20sypply/DPS-800GB%20A%20PSU%20eng.htm

• This does not work on the DPS-750RB A – spuder Apr 1 '17 at 4:40

Check out Gigampz they sell break out boards for HP power supplies, among others, you just pop on the adapter and you are good to go plus you get some nice screw terminals to attach you wiring too and you can even control it using a Arduino or Rpi using the 4 pin header. Their site is http://www.gigampz.com

• Thank you for the tip. Never heard of them but I'm sure going to check them out. – Tonny May 22 '16 at 13:30

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