/ Sign-up
Your question

SYS_FAN low voltage

  • Motherboards
  • BIOS
  • Fan
  • Hardware Problem
Last response: in Motherboards
December 15, 2012 9:37:35 AM


Technical (newbie) question.

Gigabyte GA-Z77X-UD5H
SYS_FAN1 says pin1 = GND and pin2 = 12V.
I only measure 7.72 V, resulting in a fan (3 pins) speed of 550 RPM i.s.o. #1000 RPM.
The BIOS doesn't show any settings to be modified in order to change voltage on SYS_FAN1.

Here the manual:

Page 27 says that pin2 is "+12V/Speed Control", but I don't see any possibility to change the speed (neither in BIOS, nor manual).

Is this motherboard hardware problem or do I miss something?


More about : sys fan low voltage

a c 79 V Motherboard
December 15, 2012 10:49:05 AM

Speed Control means the voltage depends on the temperature. Install the Gigabyte windows utility and you get the settings.
December 15, 2012 8:47:46 PM

Ok. Thanks. I noticed only now that in fact the fan starts up with 380 RPM (cold PC) top 600 RPM after 5 minutes power up. Do I need the Gigabyte windows utility or is it also possible to manipulate the voltage of pin2 SYS_FAN1 using BIOS? I ask because if I don't use Windows (e.g. Ubuntu), am I also able to change the voltage?
December 15, 2012 8:57:35 PM

... later ...

I noticed that setting "1st/2nd/3rd System Fan Speed Control" to "Disabled", I get my 12V !!!

Thanks for the kick!