Power pin out for HPE 12x E3.S NVMe backplane for Gen11 DL385 DL345 ML350?

[CPNXP]

I bought one of these backplanes off ebay cheap to use in a custom enclosure and I've been having trouble finding the power pin out for this board. I have parts to crimp an adapter so I can connect to a standard ATX PSU. Anyone with access to one able to give me some voltages for a rough pinout? Since the cable comes directly from the mobo I'd suspect some of the pins are for sense and status which I don't really care about, just want to see if I can get it working with power and some direct data cables.

HPE's pages not too helpful but this is the cable I need the pinout for
https://support.hpe.com/hpesc/publi...UID-743580D6-7038-4BA5-9BBD-0CB8224B875D.html

The data cables seem to be normal SFF-8654 8i cables.

 

[nexox]

Can you post a picture of the back side of the PCB around the power connector? And do you have a multimeter you could use to do things like checking continuity from that SMD fuse below the connector to the connector pins, and between the pins? From what I see it kind of looks like a single voltage on the bottom row of pins, which points towards 12V, with the top row probably all ground.

 

[CPNXP]

I do have a multimeter but my knowledge of EE isn't great, just enough to be dangerous. I was able to determine at least which pins are ground by checking them to the shielding on the data cables and to the screw ground points on the upper corners. Tracing to the fuse was a great idea and got me 3 more pins.

Using my diagram above, Pins 8,7,6 are all ground and are contiguous with each other. Pins 4,3,2 are likely 12v and are contiguous with each other and the fuse. This leaves pins 1 and 5. Pins 1 and 5 do not have any continuity with any other pins or each other. Pin 5 seems to be connected to a tiny resistor (R867) and tiny capacitor (C272) beyond that I can't really tell where that trace is going. Pin 1 I've no leads on at all. I've removed all the stickers to give a better view of the connector backside on top of the board. Pin 8 being square on the front like this pretty much confirms ground besides all of the other evidence.




So Far:
2,3,4 are very likely to be 12v
6,7,8 are confirmed ground

1 and/or 5 may be some kind of presence sense for the mobo although I'd like to rule out any low voltage if possible before I build my adapter cable.

 

[nexox]

The other two may be i2c data lines, perhaps probe around the two ST micro controllers to see if they connect around there.

 

[CPNXP]

Pin 5 seems to be connected to the micro controller at C287. As for Pin 1, I was unable to find any exposed point it has continuity with after several attempts. I'm leaning towards them being for i2c based on the connection to the micro controller. Now I'm just waiting for a few parts to come in and then I can crimp my power adapter cable to test it out. I'll probably just connect the 12v and ground to see if that's enough to get it powered on. The other other thing I would suspect p5 could also be 3.3v since that is the aux voltage called for by the EDSFF spec. Main power is 12v.

 

[nexox]

You could probe the 3.3V line in an edsff socket to see if it's directly connected to the power socket, I figured they would just throw a voltage regulator on the backplane to supply that though.

 

[CPNXP]

Thanks @nexox for the help. I was able to get the backplane powered up and a drive to link using only the 12v and ground pinout.

For anyone coming across this in the future:
Backplane is HPE PN: P65766-001

pinout using above diagram:
2,3,4 12v
6,7,8 ground
1,5 suspect i2c but was unable to confirm

Data lines are standard SlimSAS PCIe 4 cables (SFF-8654 8i to SFF-8654 8i) need to be bifurcated to x4x4

I took a short EPS-12v extension cable and cut one end off and removed two of the wires and crimped on the new micro fit pins (Digikey PN: 2987-CP3508S0010-NH-ND and 2987-CP35TN21PESCT-ND) to make the adapter cable. EPS-12v was chosen vs PCIe power to not need to deal with the sense pins.