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Optiplex 7070 micro CPU Fan header
I'm using a fleet of Optiplex 7070 micro's (210-ASEF) as part of a data acquisition system. Each 7070 is housed within an aluminium enclosure along with custom electronics. We are running into temperature problems with the 7070s, with them consistently above 80 degrees at ~50% load, and sometimes getting above 90 degrees.
I am looking into resolving this with external fans mounted to existing cutouts (for passive airflow) in the aluminium enclosure (there is already a cutout for the 7070 front panel and a large cutout for exhaust airflow suitable for 2x60mm fans). However, I would like to avoid running an additional 12V supply into these enclosures (currently everything is powered off the 7070s USB lines), so am looking into splitting the CPU fan header within the 7070 to run 1 or 2 additional fans. Thereby allowing me to run them @12V and potentially at a higher power than I would be able to off the 5V USB lines.
However, I am having trouble getting information on the header used on the motherboard - it looks to me to be similar to a JST XH series but I can't be sure. Also if there is any information available on the current rating of the CPU fan header that would help selecting fans to prevent damaging the 7070.
andrew.marshall
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August 6th, 2020 05:00
Thanks for the detail @speedstep. Pinout isn't so much of an issue as I'll have to make a custom cable assembly anyway, and the PWM, 12V and GND signals can be pretty easily identified with a multimeter.
The more challenging part is getting a connector that will fit the header - I think i'll just have to buy a few options and see what fits best. They seem to be using something similar to a GPU fan header rather than the usual 0.1" pitch fan headers.
speedstep
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August 6th, 2020 05:00
You cant order it its OEM custom so what you do is cut the wires and make custom breadboard.
You dont need to use a meter because the color of the wire lets you know.
if you arent cutting the cable then you need to buy an extra fan and cut the wires off and use that. Or remove some insulation and cut and tap into the wire adding heat shrink tubing and a fan socket header with wires.
https://www.amazon.com/Pocaton-Female-Socket-Connector-Cooling/dp/B073XJV5L9/
https://www.amazon.com/CRJ-Voltage-Step-Up-Sleeved-Adapter/dp/B081K8LBH3
speedstep
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August 6th, 2020 05:00
Dell does not support pinouts for anything anywhere ever.
Dell fans often use proprietary wiring order for 3 wire or 4 wire fans.
The wire colors tell you what is what.
Blue = PWM
Yellow = Tach
Red = 12V
Black = Ground
andrew.marshall
3 Posts
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August 11th, 2020 00:00
So a quick update in case anyone else is trying to do something similar.
Looks like the header is a JST PH-4 (https://au.rs-online.com/web/p/pcb-headers/8201434/).
The corresponding connector is a JTS PHR-4 (https://au.rs-online.com/web/p/wire-housings-plugs/8201478/). This of course requires a special crimping tool if you want reliable connections but you can also buy pre-made wire assemblies. (I'm using https://core-electronics.com.au/stemma-cable-150mm-6-long-4-pin-jst-ph-cable-female-female.html)