Hello,
I ordered this switch for me and myself and for me the fan was also too loud.
I disassembled the switch and the part number on this fan shows that it is build for 4000 - 10000 rpm. So it's loudness reaches from very very loud to very super mega loud!
The Fan IS speed controlled!
next to the fan connector there is an PTC or NTC (blue, very small part) when you touch it (and warm it up with thefinger) the fan speed increases.
Because the fan does not change the rpm during boot (as it do on old, solid HPE Switches) I am sure the control circuit is a dedicated and analog circuit and the os of this switch can not control the fan speed rpm.
The connector's pinout is compatible with any mainboard / intel fan (4 pin PWM).
For test purposes I Connected an genuine intel CPU fan and it also runs normally.
So, I decided to build my own upper case with a 12cm x 12cm hole on the top right with an arctic cooling 12x12 4 pin PWM fan. It is blowing there inside the switch and the air flow is coming out on the left side through 2 holes.
This fan runs at approx 1000rpm and generates much more airflow than the small 4x4cm fan at much more rpm does.
only thing is, the air flow goes into the other direction. Normally the airflow is from left to right, the fan blows the air out of the switch and the NTC / PTC next to the fan can see how much heat is produced by the switch and can control the fan speed.
now the NTC / PTC is only measuring the intake air and can not react on the switch load.
Also the problem at the moment is, the Tacho signal is so low due the low fan speed, that the switch interprets the fan as defective and displays an error (red blinking light and fan error in the logs)...
When I pull out the PIN 4 (PWM control for the fan) the fan accelerates to its maximum speed (1800rpm) and the switch goes back to normal state. But at this moment the 1800rpm are totally overdosed with this 12cm fan and you can hear it and see in its power consumption.
Now I am planning to rebuild my own case, set the fan to the left top, so the airflow is as normal and the PTC / NTC measures the outtake temperature and I am planning to build (or buy) an small frequency generator (NE555) to simulate a solid and higher fan speed to the Switch to let the switch be in normal state.
Hope this helps anyone
thx
Dirk