dl380 gen9 8sff cage 747592-002 Power layout / connector

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Hello together,

I’m new to the forum and in the process of preparing everything form my build.
I was lucky and could strip down an HP DL380 Gen9 server. I can’t use the rack chassis and original DL380 mainboard for various reasons.
I would like to reuse the 8SFF HDD Cage, or better so say the backplane of it. I really like to use the 2XSFF-8087 connectors instead of 8 single once + power.
Power is the problem; it does not seem to be a standard connector.
I did a bit of measuring on the backplane with a multimeter. I attached a picture of the backplane where I numbered the Pins of the power connector.

This is what I found out so far

1 ? diode to 6
2 GND bridge to 5 -> SAS P4-6
3 12V bride to 4 -> SAS P13-15
4 12V bride to 4 -> SAS P13-15
5 GND bridge to 2 -> SAS P4-6
6 ? diode to 1

For the SAS Pinouts I used this drawing.

Measurement from the diode
v-com
6-1 -> 2,253 V
1-6 -> 1,990 V

I got 2 different power cables from the DL380 Gen9 Mainboard towards the 8SFF Backplane. The go with HP Product number 747561-001 and 747560-001.
on 747561-001 Pin 6 is empty
on 747560-001 Pin 1 is empty


My goal is to the cable and put an molex connector on it to power it from an standard ATX power supply so that I can the HDD cage in my new NAS.

Now comes the tricky part. I need to figure out how to wire it. I guess ground and 12V is easy. At least from my measuring. My guess that the backplane splits the 12V in 2 different locations by 4 to get 3V for each of the 8 HDD slots.
so I would assume the last Pin 1 or 6 is 5V

I couldn’t find any electrical drawings on the backplane nor of the mainboard of the DL380 Gen9.
If anyone has one that would be perfect. Or maybe has been down the same road. I currently don’t have access to a DL380 Gen9 to “just” measure it.
And I don’t want to just assume an shorten the backplane, my new mainboard or power supply

Maybe one of you could help me out.

 

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So I got my handys on a working dl380 gen9 today.
I used my Multimeter to messured a bit.
Pins2-5 are confirmed as above.

That I tested both other cables with Pin1 and Pin6 empty.
On 747561-001 where Pin6 is emtpy I get 3.3V on Pin1
On 747560-001 where Pin 1 is emtpy I get no voltage against both grounds.

I tryed to messure if These 2 Pins are connected to each other on the mainboard. That is not the case.

 

[homer27081990]

Measure pin 1 and 6 at boot, it most likely is a numbering control pin (sas ports 0-7 at HIGH 1 FLOAT 6 sas ports 8-15 at FLOAT 1 HIGH 6 with HIGH at +3.3VCC?)

 

[homer27081990]

Found this

 

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thank you very much.
sadly the Gen8 LFF uses a 8 pin connector, whereas the gen9 sff uses only a 6 pin.
the strange is that the pin layout of the 2 cables are different depending from which connector on the mainboard they are comeing from.
for the one wirh pin 1 used and the +3.3V i found that the pin 1 lane is connected to an IC on the backplane of the caddy.

i used my multimeter to find a corrosponding pin for pin 6. so far no luck. not to any IC on the this side of the backplane nor any other visable componend on the PCB. also not any connector i could find on the inside of the hdd cage.

since the DL380 Gen9 i got the backplane of has 3 HDD cages. 2 are connected with a powercable where pin 1 is emtpy and the 3rd with pin 6 empty. all 3 are working fine. so i assume you need either pin1 (747561-001) or pin6 (747560-001)
the powercables normaly to the connectors 10 in this drawing. 747561-001 with pin1 is plugged in the "upper" connector 10 (where also 13 and 14 are). the other 2 with pin6 (747560-001) connect to the lower ID10.
the upper one is a 10pin connector the lower once are both 5pin.

Measure pin 1 and 6 at boot, it most likely is a numbering control pin (sas ports 0-7 at HIGH 1 FLOAT 6 sas ports 8-15 at FLOAT 1 HIGH 6 with HIGH at +3.3VCC?)

i read it several time, but still don't really understand what that means.

 

[ascii-]

I build myself a Power cable with
P1 +3.3V
P2 Ground
P3 +12V
P4 +12V
P5 Ground
P6 empty

Nothing blows up let's say it this way.
But the drives are not spinning up.
The Pins from the SAS Part of the backplane go to the powersupply. Ground and +12V.

I Was really hopeing I can use the backplane