Power supply fan started to periodically spin up and stop spinning every 5 seconds.

[Jozef__]

Hello,

Power supply fan on desktop HP Z2 G9 TWR (5F0M6EA) started to do periodic sounds:

"fan started to periodically spin up and stop spinning every 5 seconds."

Here is the brief video of the fan itself

https://drive.google.com/file/d/1q-qxrpA3haNb-TaLl6WwP8re7caBvwEi/view?usp=sharing

Beside the sounds, everything looks in order. No other problems with the power supply.

So far I have tried to upgrade to newest BIOS but no joy.

Also interesting thing ... when I plug in some external disk via USB and start copying something FAN is spinning steadily.

Have you ever seem something like that?

Desktop is still under warranty. I am considering to request for the repairs or so but wanted to try to ask you guys first.

Thanks in advance.

Regards,

Jozef

[DGroves]

your fans are most likely operating normally, the bios is programed to check various temp sensors located in various parts of the system and they tell the system when to increase which fan till the reported temp is below the trigger threshold

your power supply is set to not enable the fan until a set semp is detected

you power supply appears to be right on the border of the fan enable setting based on the pre defined setting which is turning on the fan and one enabled it's lowering the reported temp to fan off almost right away this is normal but can be annoying in terms of noise i suspect the room temp where the computer is  has changed just a bit based on your local weather and the bldg heating temp setting

your fan stays on while doing something like copying to a usb drive because your now drawing just a bit more power and causing more heat so the fan stays on at a very low rpm to cool the power supply

[Jozef__]

Hi DGroves,

That is an interesting point. I will try to load the PC CPU or change the ambient temp a little bit if something changes.

But it looks unbelievable to me that current PC placement hit the exact temp spot for doing this ... kind of crazy.

Thanks for the insight.

[Jozef__]

I have tried to use blow dryer to increase the temperature of the air inside the power supply but it didn't change the behavior.

But when I tried to load the CPU with specialized tools (to 100%) or native HP CPU test for a several minutes, power supply fan started to rotate constantly. And finally stopped turning on and off again every 5 seconds. Also other fans spin up loudly - as expected. So it looks like if the PC is not under load or just mediocre loaded the problem occurs constantly.

Seemingly it has nothing to do with the room temp equilibrium (in the room the temp is regular 24 degree Celsius.).

I will try to call the support as it is still under warranty and the PC operator is complaining about the continuous sounds. 😞

Regards,

Jozef

[Jozef__ · Accepted solution]

Just wanted to let know how was this issue resolved.

I have requested for warranty PSU replacement and new PSU resolved the issue.

Jozef