Hardware Changing over fans in a network switch

[garyw]

Maybe someone with more electronics skills than I have can help me out here.

I've got a network switch that has two insanely noisy fans in it. I decided to swap them out for some quieter ones. The ones that others have said that they've used were duly ordered and arrived today.

I removed the noisy fans and installed the new ones and they don't work. The only difference I can see is that the ones in the switch are 12v 0.12a and the replacements are 12v 0.07a - does this make a difference?!

Thanks.

 

[Urwumpe]

I removed the noisy fans and installed the new ones and they don't work. The only difference I can see is that the ones in the switch are 12v 0.12a and the replacements are 12v 0.07a - does this make a difference?!

Possibly yes... does it have a speed control?

 

[Keatah]

Those numbers are current consumption specifications. The newer ones are consuming less current than the old ones. 120mA vs. 70mA. And this should not make any difference.

What could be the problem? Perhaps pinouts and polarity on the connector. Speed control and sense lines could be mis-wired, incompatible.

Posting info about the mainboard/model and the new fans, such as brands and model numbers would help.

 

[garyw]

What could be the problem? Perhaps pinouts and polarity on the connector. Speed control and sense lines could be mis-wired, incompatible.

Just took a closer look at that and it does look like the red and black wires are reversed on the supplied fans vs the new ones. I'm going to test that out now.

:blink: Well........ All that looking and I never noticed those wires were reversed before. I just swapped the wires round, tested and the fan fired up first go!

Thanks Keatah!

 

[Keatah]

Just bringing to your attention that there are several different kinds of fan connectors. These links serve to illustrate some of the differences:

http://www.interfacebus.com/ATX_Motherboard_Fan_Connector_Pinout.html
http://www.intel.com/support/motherboards/desktop/sb/cs-012074.htm
http://pinouts.ru/Motherboard/MbCpuFan_pinout.shtml

And I've seen other non-standard pinouts for graphic card fans and set-top-boxes..