5820 - Internal 12V Source POWER_CPU1? & POWER_REMOTE Question

Question

Two issues I have had zero success searching for clues regarding the function of the empty sockets identified in the title. First, there are no spare sources of 12 volts remaining in this system. In the process of installing water cooling on this 5820 XEON W-2295, it requires a 12 volt source (ideally a 4 pin Molex). There is an empty socket on the power distribution board identified as "POWER_CPU1". Its twin(POWER_CPU0) is connected to the MB. The question is, can I use it to get the required 12V for the water cooler's function requiring it? FYI - this 12 volts is used for monitoring temps, creating the shut down trigger, NOT to run a pump. If it is available to tap into 12 volts, does anyone have a pin out for this socket so I can figure out what pins are needed to source the 12 volts? FYI, the cooler system is Koolance EX2-1055.

Next, also related to the cooling system, it has a wire with two, two pin connectors (one male/one female) identified as an "ATX Pass-through". The original instructions wanted this to be connected to the power switch, then the switch's connector would attach to the remaining connector on the "pass-through". The function of this wire was to communicate a shut down command if the system's temperature rose to critical levels. Given the way Dell wires the system, there's no way to access power switch wiring. What I did find online was a 5820 being used for crypto mining and using the same brand of cooler as this install and they connected one of the pass-through's connectors to a 2 pin socket on the board (not in use) identified as "PWR_REMOTE", claiming it would function as intended - the temps go critical and the cooler triggers the shut down command. What puzzled me about that approach is the second connector on the "pass-through" goes unused in that configuration.

Can anyone offer any guidance on these issues? Essentially, can I use the CPU Power socket to get 12 volts (and the pin outs that would enable identifying the 12 volt source) and second, will the Power Remote connector trigger a shut down if the cooler commanded it with only one connector utilized.

Thanks,

Dennis

mazzinia_ · Accepted Answer

Hello,

so, the Power_cpu1 is used in the 7820 to power the 2nd cpu if the relative cpu board is installed. In the 5820 is not being used, so yes, you can draw from it ( but I don't know the pinout, sorry ). Bear in mind the wattage there is enough to power a 250W cpu.

About the Pwr_Remote , is used in conjunction with the Teradici remote control card, to control turning on/off the workstation. It can be repurposed

dmfcavu · Answer

@mazzinia_​ thanks very much for the reply.  I was able to locate a pinout for the 10 pin for a 5810, likely the same for the 5820.  Also received the cable to use the connector as planned. The 10 pin connector is wired - Pins 1-5 are ground (black wires), 6 is unused, 7-10 are positive. Attached is the pinout diagram for a 5810, maybe this is of use to someone. Regarding the PWR_REMOTE header - I did review the Teradici section earlier, and was hoping it would be a painless solution to the problem.  If you have any insight to how it can be repurposed, please share it. I'm digging into this deeper after finishing up here.  This is way outside of my space, but I'm guessing there's a specific command required to trigger the shutdown, and Teradici also uses it to powert up, which is not required for this device.  Koolance seems to think connecting anything to that header will disable the power button, which does not seem likely to me.  I'm going to request information from Koolance on the command they send - format, etc., perhaps that will shed some light on it.  Also want to see if it can be tested to confirm it works. Thanks again, appreciate the help.

mazzinia_ · Answer

@dmfcavu​ I'm not sure about the repurposing, but in the teradici instructions they point out to not plug the cable in the 2 pins that clear the bios  ( because otherwise by issuing shutdown/start , it would clear the bios ) , so this makes me think that the action performed is a simple jumper effect , and so the pwr_remote follows a simple jumper effect. Quick close the contacts to power off , quick close the contacts to power on if in a powered off state, like pressing a button ( but this is just me inferring )

uma299792 · Answer

Hi Dennis/ @dmfcavu

Apologies for what is a rookie question. You had mentioned that "There is an empty socket on the power distribution board identified as "POWER_CPU1". Could you please tell me if the port I highlighted in the attached image (55475.jpg) is the one you are referring to? I cant seem to find the label for this port. (Tagging @mazzinia_ too in case you are able to help)
Many thanks

dmfcavu · Answer

I believe you are looking at the correct connector. It was hard to see, if you remove the board you'll locate it.  I recently sold the remnants of my 5820 or I would check it for you. There's a number of PC mod businesses that make custom cables, that made one for me that converted it to a SATA power source and it worked great. Rookie question? Nope, you're in deep! Good luck and have fun!

uma299792 · Answer

Thank you 🙂 I got a cable from comeap which is supposed to work- the aim is to tap this to power a 5080 as one of three pigtails.

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5820 - Internal 12V Source POWER_CPU1? & POWER_REMOTE Question

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