Chassis fan not detected in BIOS

graphicsgriffin

Distinguished
Feb 20, 2011
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Hi everyone. Hope you are all happy with your PCs!

My system has an Asus Sabertooth 990FX R 2.0 motherboard and the Corsair 600T case which comes with three chassis fans. All of the three chassis fans are connected to the motherboard's CHA_FAN connectors which are 4 pins, while all of the fans have 3 pins. Fans connected to CHA_FAN1 and CHA_FAN3 are showing in BIOS and ASUS Fan Xpert and their speed is controlled successfully. However, the rear chassis fan which is connected to CHA_FAN2 is not detected in either the BIOS or the software. All of the three chassis fans are spinning and working all right. What could be the reason?


Asus Sabertooth 990FX R 2.0
FX 8350
32 GB DDR3
RX 480
Corsair 600T case
Corsair 650 watts PSU
 
Problem with header could cause that, or the fan cable. One of the pins is used to detect if fan is connected to the header. If that pin is not working, or the corresponding cable in fan not working, mobo would not detect fan. Switch fans. If problem follows fan, it's the fan now working. If problem stays on FAN2 header, it's most likely header not working.
Of course it *could* be some kind of software problem (ASUS utilities :) ), but since it happens at BIOS too, I'm inclined to consider it hardware problem.
 
Thanks for replying. I will try to connect the rear fan to header CHA_FAN4 and see if it gets detected or not. Also I will connect one of the detected fans to the header in question. Will reply shortly with the result.