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Silent Fan

Posted: Tue Oct 30, 2018 4:52 pm
by Shanther
I can't wait for the new odroid but until then I have my XU4 and even afterwards I'm not getting rid of it. I want a quieter fan option and I keep seeing the same fan mentioned. I want to know if this is a good wiring example. I can't find any info on the chipthe yellow wire is connected to. Is the yellow wire ok?

https://mobile.twitter.com/ardadev/stat ... 53/photo/1

Do you have better options that let my current fan speed configurations stay as they are? Thank you.

The current fan needs replacing as it rattles and needs a tiny tap to stop it for a while. The sound is driving everyone crazy.

P.S. I'll be buying the new one once a DietPi is released for it. That OS is a lifesaver.

TLTR: I found a fan mod I want the yellow wire explained to me. I am also seeing if a better wiring setup is known that uses the same plug and configuration as the normal fan.

Re: Silent Fan

Posted: Wed Oct 31, 2018 2:26 am
by rooted
That is a noctua fan and they are great but a bit expensive. AFAIK you simply wire the three wire fan with two wires leaving out the RPM monitor wire and it will work multispeed just like factory.

You will not likely find a fan with that tiny molex connector, you must add it.

Re: Silent Fan

Posted: Wed Oct 31, 2018 8:19 am
by Shanther
rooted wrote:That is a noctua fan and they are great but a bit expensive. AFAIK you simply wire the three wire fan with two wires leaving out the RPM monitor wire and it will work multispeed just like factory.

You will not likely find a fan with that tiny molex connector, you must add it.

I already bought the Noctua fan. I wanted silent and I know that costs more then stock.

So the yellow wire doesn't even need to be plugged in? Can safely snip the red and black wires and use the stock fan plug?

Re: Silent Fan

Posted: Wed Oct 31, 2018 12:22 pm
by phaseshifter
YES just use black/red wires.. discard the yellow/green/blue..etc wire black and red are all that matter....

you can change the fan script..codes ..here look at this thread...

viewtopic.php?f=52&t=16308&start=100&hi ... +fan+speed

Re: Silent Fan

Posted: Wed Oct 31, 2018 7:09 pm
by Shanther
phaseshifter wrote:YES just use black/red wires.. discard the yellow/green/blue..etc wire black and red are all that matter....

you can change the fan script..codes ..here look at this thread...

viewtopic.php?f=52&t=16308&start=100&hi ... +fan+speed

Good to know. As for the script I really do NOT want to change it as my coding skills are non-existant. I use DietPi because it simplifies Linux for what I need.
I managed to make this before I found DietPi and even then at that point I still needed a few of these scripts. I didn't make any of the code but I did find a lot online and pieced it all together.

viewtopic.php?f=52&t=26267

What helped me find DietPi is the quick clock speed changing setting. As soon as Plex started processing everything the CPU would overheat. Now it just runs slower due to the heat. That and I live in Australia so we have some nasty hot days here.

The fan script I am using is modified from the previous one I had for Jessie. It is by far the simplest code anywhere. This is it: https://dietpi.com/phpbb/viewtopic.php?f=11&t=5103


Glad to know that the yellow wire won't be needed and the normal script will work just fine. Thank you. I will reply here if any issues occur.

Re: Silent Fan

Posted: Sat Nov 03, 2018 9:15 am
by Shanther
Stock Fan:

CPU speed clocked at 1.4GHz idle
Temp 41'


Noctuna Fan:

CPU Speed clocked at 1.4GHz idle
Temp 35'

CPU Speed clocked at 1.4GHz Streaming media
Temp 38'

CPU Speed clocked at 2.0GHz streaming media
Temp 42'-44'


This fan is beautiful.

Re: Silent Fan

Posted: Tue Mar 05, 2019 10:32 pm
by roots
rooted wrote:
Wed Oct 31, 2018 2:26 am
That is a noctua fan and they are great but a bit expensive. AFAIK you simply wire the three wire fan with two wires leaving out the RPM monitor wire and it will work multispeed just like factory.

You will not likely find a fan with that tiny molex connector, you must add it.
Hello,

just for my curiosity why you recommend to cut the RPM monitor wire? Thanks

Re: Silent Fan

Posted: Tue Mar 05, 2019 11:13 pm
by rooted
roots wrote:
rooted wrote:
Wed Oct 31, 2018 2:26 am
That is a noctua fan and they are great but a bit expensive. AFAIK you simply wire the three wire fan with two wires leaving out the RPM monitor wire and it will work multispeed just like factory.

You will not likely find a fan with that tiny molex connector, you must add it.
Hello,

just for my curiosity why you recommend to cut the RPM monitor wire? Thanks
Because it's not needed, the XU4 uses pwm on the power wire afaik.

Re: Silent Fan

Posted: Wed Mar 06, 2019 12:51 am
by wcairns
The yellow wire is for tachometer feedback, so the controller knows how fast the fan is spinning. The XU4 does not have that function on the fan header, it provides PWM controlled power to the fan only. It is not aware of how fast the fan is spinning.

Sent from my LM-V405 using Tapatalk

Sorry for the edits, that's what I get for using my phone to reply.


Re: Silent Fan

Posted: Wed Mar 06, 2019 4:58 pm
by roots
Yes clear. I could swear that the odroid XU4 has the tachometer pin also.
Yesterday evening I took a look at my odroid and I realized that my question was stupid :) but anyway I hope your answer will help somebody.

I'm still trying to understand how the fan speed is controlled. Is it controlled in current?
I'm asking because I don't know which kind of noctua fan should I choose.

Re: Silent Fan

Posted: Wed Mar 06, 2019 5:10 pm
by mad_ady
The power pulses with a specific frequency and fill/duty cycle (wide or short pulses) powering the fan for longer or shorter duration of time (in a second). This causes the fan to turn with various speeds. You should look for a 5V PWM fan.

Re: Silent Fan

Posted: Wed Mar 06, 2019 5:15 pm
by roots
So it must be a PWM fan... but a lot of people are buying NF-A4x10 5V which is not a PWM fan.

Non PWM fan: you can still control the fan speed in on/off pulses lets say. Probably the life of the fan will a little shorter.
PWM fan: you will need a +5V constant from the PCB and the PWM pin must be connected on the fan connector. This is the ideal solution. But I think nobody use it.

I really have to check the fan signal on the oscilloscope.

Re: Silent Fan

Posted: Wed Mar 06, 2019 5:27 pm
by mad_ady
As far as I remember I'm using two noctua fans 5V with pwm.

Re: Silent Fan

Posted: Wed Mar 06, 2019 7:26 pm
by roots
Based on the schematic:

https://dn.odroid.com/5422/ODROID-XU4/S ... OT1606.pdf see sheet 4
There is a transistor and a capacitor. It looks like the cooler is controlled by the PWM. The PC fans uses brushless DC motors, with the hardware driver (IC) inside them.

Theoretically you can use both kind of fans ( PWM (4pins) and non PWM(3 pins) ). In both cases you will use only the supply pins. And the fan should work.

Correct me if I'm wrong.

Re: Silent Fan

Posted: Wed Mar 06, 2019 9:23 pm
by mad_ady
I remember somebody complained that a non-pwm fan did not start.

Re: Silent Fan

Posted: Wed Mar 06, 2019 9:58 pm
by roots
I don't understand why... I will first check the fan signal on the oscilloscope... at least one thing will be clear...

Re: Silent Fan

Posted: Thu Mar 07, 2019 1:18 am
by rooted
You can use both types of fans.

Re: Silent Fan

Posted: Sun Mar 10, 2019 8:15 am
by roots
Thanks guys for you support.
I will try to summarize my experience with the others users which are still struggling with the fan.
I have an Odroid XU4 with a heatsink like this one: https://www.aliexpress.com/item/4-piece ... TEM_DETAIL

I bought a Noctua NF-A4x10 5V: https://noctua.at/en/nf-a4x10-5v
It's a 3 wire fan: Black:GND, Red:Power supply(+5Volts) and Yellow:Tachometric signal
You can use the fan without the Yellow wire.
Regarding the connector (Molex 51021-0200 / 1.25mm pitch) it's a pain, don't try to use a pin header with the 1.25 pitch, the pins of the male connector from odroid are not circular in section, so you cannot plug a normal pin header. If you think that you can use only the pins from molex (without the housing), forget it, because they will not fit perfectly, only take a look here: https://www.molex.com/pdm_docs/adobe3D/50079-8000.pdf. Pins can be used only with a housing otherwise they will slip from the connector, and you don't want this.
I made an improvisation from some other connector "carved" with a blade. Until I will order some molex connectors.

This fan worth the money, it's very silent, I cannot compare it with the odroid original fan. From now on, If I ever need a fan I will definitely choose a Noctua one.

FAQ:
Yes, the ODROID XU4 provide enough current to control the FAN.
The Odroid control the fan with a PWM signal.
You don't need a PWM fan from Noctua. The PWM fans have 4 wires.
If you fan is not starting, check the connection to the fan plug. Most Noctua fans has internally a diode for polarity protection.

Re: Silent Fan

Posted: Sun Mar 10, 2019 3:30 pm
by mad_ady
Thanks for the clarification :)