I'm having the same problem with the TL-SX1008, especially with the fan constantly changing its speed causing the constantly changing frequency of the noise.
I contacted TP-Link and their response was to move it to a place with a lower ambient air temparature. The temp in my office is about 25-27C which I don't consider to be high, so I'm not impressed with their suggestion considering that the specs say low noise operation. I think that they would have been better off avoiding the intelligent speed control and just using a constantly running low rpm, low noise fan...
At this point I've considered returning the switch back to Amazon, but the functionality is exactly what I want and its working well except for the noise. Also, I can't find any other switches that have the 8 RJ45 1G/2.5G/5G/10G ports that I need. So, being a EE, I've decided that I'll just bugger around with it to fix the fan noise.
So, has anyone sucessfully replaced the fan with a noctua nf-a4x20flx and eliminated the problem?
In any case, I've ordered a noctua nf-a4x20flx. It should arrive in a couple of days from amazon and I'll see what happens when I replace the existing fan and post the results.
I'm not very conerned about the air flow rate since, as near as I can tell, the fan seems to be operating at very low level. The switch operating temp range is 0–50 °C (32–122 °F). When the switch boots the turbo sounding fan noise shows what happens when the fan is on full (10cfm) which is what would happen with a 50 °C ambient. The switch is rack mountable which accounts for need for the 50 °C operating range since racks tend to have high ambients. For desktop operation in a climate controlled location like my office the fans are clearly operating at a much lower level, probably less than 50%. So I figure that the 5 cfm of the noctua nf-a4x20flx should be adequate for my office environment. Worst case is that I may have to bypass the speed control and just hook that new fan to the 12v rail to keep it at a constant 5cfm.
Dave...
