SM2 power module noise


Why is the fan of the power module so loud/making noise from power up (fan 100%?)?
That small fan makes a lot of noise as soon as the power switch is turned on.
Is there no temperature controlled fan possible?

I like to change the fan for a Papst, Zalman or other brand with bigger size but much lower noise. So far i did not open the power module. Is there someone who can tell me more specs (voltage, amps) of this small fan so i know the needed airflow and connection?

Is there a possibility to make a fan-less power module in near future?

And how to switch off that fancy light in the power module?


Good post. I just received my A150. Does a great job, BUT the fan on the PS is so noisy. So if we cannot modify the existing PS. There are fanless PS you can get hold of so I might venture that way. For that I need the connector and a cable.

Where can I get the connector? Can I have the the details for the connector and the pin-out please.

I asked the support day before or yesterday for this info´s, waiting for feedback.

I believe the SM Power supply communicates to the controller using the CAN bus so it can tell the controller a power outage is coming in the split seconds before power flows out of the capacitors in the supply. The breathing light also conveys other info about the state of the power supply. @whimsycwd?

Thanks, that’s interesting. That puts using a fan-less PS in a different light. I guess I can forego the power outage feature just to get som quiet in my 3D shop. I found one at Mean Well (Taiwan, US, etc) that is available in Sweden.l The UHP-350-24 gives well regulated 24V up to 14.6A. A professional PS.
IS there more information on the breathing light??

Still need the pin-out and where to get the connector.

I had contact to the support. They have to ask the electrical engineer about how to exchange the powersupply.
I also asked about the 4pins, canbus etc.- i wait for it @Edwin

Indeed, to loud for me.
Please let us know when there is news about this item…

pushed the message again, looking forward to a reply @Edwin

Hi @xchrisd @Wallgarden @Tone We have noticed this noise issue for a long time and are considering to make some modification on it. I will forward this issue to our electrical engineer again and ask for information about the ongoing process tomorrow.


The Newest information about the fans in PSU:

We are considering the lower the fan speed to reduce noise. In addition, the fan can reduce the heat generated by the self-consumption power on the circuit board and the heat generated when working. The fan speed is calculated before the production. Some related tests are on the way.


Thank you for the information.
Look forward to further reports.
Hopefully there will be a solution.

Hi @Edwin,

Will the Fan setting be fixed via the firmware or replacing the fan?

New info about the power supply fan’s noise.

The engineers have proved that they are doing the tests on some more silent fans, and the result will be reached in the near future. Once the new PSU is in massive production, we will make it available to your guys.


OK. Thanks. Good so far. How much will the noice be reduced? Can you make the fans available with an exchange instruction?
Can we get the fan in Europe?

How about an upgrade kit for the technically capable?

How much will the noise be reduced?

  • Our engineers are still doing the tests on the fans.

Can you make the fans available with an exchange instruction?

  • A instruction video will be made when the silent ones are made.

For technically capable changing fan is not a big deal. No instructions needed. Problem is that small size fans are louder than bigger ones because they need to rotate faster to make same airflow. So for good result 2 things must be done - find quietest possible fan and reduce fan speed when power supply is cool. For example turn on low speed at 40C inside temperature and increase speed if temperature rise. If I some day make this this upgrade I will publish it.

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@Edwin what are the CFM requirements for the fan? I can source a quieter fan for testing.

What I have seen has the installed fan an airflow of 6.7 CFM

With the mod on Thingiverse for a backplate suited for a fan with the dimension 40x40x20 there are also other and maybe better possibilities?