Help w/ "quiet" 40 MM 5V fan options (10-20mm thickness).

[spcruzzie]

I have a lan switch with a bad fan. I am trying to replace it with a "quiet" fan that does not sound like a dentists drill. Are there any equivalents to the quietness of the noctua 40mm fan (I cant use that because it is 12v! I ordered one and tried it at 5v--no go.). http://www.noctua.at/main.php?show=prod ... =47&lng=en I do not believe there is a 12v option on the switch power supply. I think the it puts out 5v only. The whole board runs off of 5v with 3 pairs of black and red off of the internal PS and hooking into the board.

I have tried a Evercool DC-5V 40mm x 20mm Cooling Fan EC4020M05CA but I cant make it silent. It sound gravelly a few times a minute and it is a cheap single ball bearing thing. It's barely acceptable when I am holding it but when I put it in the case its a dentists drill. I tried isolating it with foam but that did not seen to help

Is there a way of making a fan controller for a 5v fan? The options I have seen at are voltage reducing ones for 12v fans that will run at lower voltage. I have not seen one 5v fan controller.

Why dont I use a 80mm 5v? It would require a lot of drilling in the thick metal case and painting. PITA. In addition I have not found any high quality 80mm 5v. If there was a very high quality 80mm 5v I might be more willing to take on the couple of hours to mod the case.

Heatsink upgrade? No real room in the switch case.

Thoughts? I figure the community here feels my pain and might have a solution.