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HP Recommended

Good afternoon,

I have an XW9400 system board with the following connectors attached (referring to the technical manual page 56):

#1: Main power (24-pin)

#47: Memory power (4-pin)

#41: Processor power (6-pin)


as well as a CPU fan attached to one of the 3-pin 12V fan connectors, a PCI-e graphics card, and a PS2 keyboard. The power supply is the DPS-1050CB A.


One thing to note is that the DPS-1050CB A does not have a 4-pin memory power connector. I used an adapter from cable P2, which features a 6-pin connector, to a 4-pin connector that fits the connector on the system board.


I should also mention that I have no case currently.


I have the following issue:

- When I switch the system on, the green light illuminates for about 2 seconds, then turns off. The system does not appear to start up (fan does not start, etc). Subsequent presses of the power button give a click in the power supply, but no other activity. Occasionally I can get the green light to illuminate again; for example, if I disconnect and reconnect power cables.

- If I disconnect the 4-pin memory power connector, then attempt to start as before, the system appears to power on (CPU fan is turned on). However, there is no signal through my graphics card. The green and red lights (so, combining to make amber?) are both illuminated continuously with no blinking.


I looked through the diagnostic procedures in the manual and did not find any solution. 


I appreciate any advice. I am not knowledgeable about computer hardware. Thank you

HP Recommended

i suspect your 6 to 4 pin memory adapter or 24 pin may not be wired correctly


pleas look at the xw9400 service manual for the proper wiring (pages 157/158)



HP Recommended

Thank you for your response. I checked and found the following.

- The 6-pin connector on the power supply has 3 wires which are black with yellow stripe.

- With the extension cable plugged in, these three wires correspond to solid yellow wires on the extension cable.

- The 4-pin connector I am plugging into the system board has a wire arrangement that matches the diagram on the manual. In particular wires 3 and 4 are solid yellow while 1 and 2 are solid black.

- I was not sure how to check if the 24-pin is wired correctly since the manual did not specify any colors.



I should have noted that the extension cable is actually a 6 to 8-pin connector, which splits into two 4-pin connectors.

One of the 4-pin connectors takes two solid wires from one single black/yellow-stripe wire that comes from the power supply (i.e., one of the three such wires coming from the power supply to this 6-pin connector).

However, this is not the 4-pin connector that I am connecting; I am connecting the other one. The one I am connecting has two yellow wires which each correspond to a distinct black/yellow-stripe wire on the power supply's 6-pin connector (i.e. the other two black/yellow-stripe wires coming from the power supply to this 6-pin connector).



Is the DPS 1050CB A the proper power supply for this board? I obtained that power supply with the understanding that it was fully compatible.

HP Recommended

the  DPS 1050CB A  should also have a a HP part number P/N : 408947-001 and is the optional 1050 watt unit


the proper stock HP xw9400 power supply will also have all of the correct power connections and not require your mismatch of adapters it's a 800 watt unit and is P/N : 408947-001


next your method of matching colors/stripes on wires is a very bad idea as you have no idea if the wires carry 12 volts/5 volts/3.3 volts get yourself a voltmeter and CONFIRM PROPER VOLTAGES are being sent to the connections on the board from the power supply if using non HP adapters/spliters




last, (or rather first!!) READ THE SERVICE MANUAL!!!! it covers which power connectors go to what locations on the board (pg -88)


if you can't be bothered to read it i can't be bothered to try helping you





HP Recommended

Good day,

In that case, I will see about procuring the proper power supply rather than attempting an improper installation.


Of course, I have already looked at the manual. As I stated, I have connected the three necessary power connectors referred to in the manual (eg pg 56, 157, 158).


Edit: Are you referring to the technical service guide document we have been referring to, or is there another document?

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