Case fan problem. PWM missing?

goblinapoel

Member
Aug 5, 2013
29
0
0
Dear all,

I have one question regarding my case fans. I have an old Coolemaster Cosmos case. It came with 4 fans before 5 years i bought it (never replaced them yet). The connectors have 3 wires only (I assume the PWM cable is missing here?)

In BIOS or in FanXpert application in windows, Fan_1 reports 0 or N/A (But I can see that the fan is actually spinning) while others about 500-800 RPM. Can these fans be controlled regarding their speed? Or shall I order new fans which support PWM?

Please enlighten me here please.
 

Euchrestalin

Senior member
Jun 22, 2007
849
0
76
The fans you have can be controlled by changing the voltage only. PWM control requires 4 wires.