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November 20th, 2025 17:10
14 Premium PA14250, fan noise as they cycle on and off repeatedly
We have about 20 PA14250 so far and we've got reports (and observed on my test system) that the fans make a buzz or whir noise repeatedly.
It looks like at low load the fans stop completely, then will turn on to a somewhat high speed and slowly ramp back down. There is a support KB doc indicating a noise problem on BIOS lower than 2.0.2 but ours are all well beyond that version and a noise persists. I don't think we ever received any with a BIOS below 2.0.2 so maybe the noise was worse or different before.
Does anyone have experience with this on their systems? I'd like to replace the fans but not sure if that will make a difference, it sounds more like a problem with the control circuit using a bad motor control profile which would remain after fan replacement. If I remove the fans the noise goes away but obviously that isn't useful outside of testing and isolating the problem.
Appreciate the community's insights here.
Margie129Palmer
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November 21st, 2025 06:19
Hello!
The fan buzz on PA14250 systems isn’t a hardware fault but comes from the control logic: at low load the fans stop, then spin up quickly and ramp down, creating noise. Replacing fans won’t help—only a firmware update or adjusting power/thermal settings to reduce stop‑start cycles can mitigate it.
khenryQ
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November 21st, 2025 15:20
I suspected as much. I'm really puzzled why the fans don't start on a slow speed. Brushless motors like all small computer fans can be started at low torque. I think the noise is from a high power setting at the initial turn-on and then it ramps down to a reasonable speed, but then shuts off entirely. (I used to work for a motor control company)
This is frankly a defective fan control profile that is more what I would expect from a cheap laptop that doesn't use PWM, not a Pro Premium anything. The firmware should be updated to modulate to a steady speed when possible and otherwise have a shallower ramp up at initial turn on. Our CEO and CFO really are not impressed with this model after 'upgrading' from their Latitude 7440 :(
Adjusting the power\thermal settings will have a pretty significant impact on power consumption either shorter battery run time or lower performance - I should be able to tell our employees to use Optimized in Dell Optimizer as we have done for years.