Can't control Case fans from SpeedFan

Hey all,

I have 2 case fans and before I had them connected to my power supply with molex cables. I wanted to be able to control their RPM's from SpeedFan so I bought 2 Molex to 3 pin adapters. I unplugged the fans from the power supply and connected them to the adapters and then connected the adapters to my MOBO (Asus P5K Deluxe) in CHA_FAN1 and CHA_FAN2.

When I started up Windows 7 after that and loaded up SpeedFan, I got a BSOD. I rebooted and everything worked fine so not sure what the BSOD was about. Unfortunately, SpeedFan still shows what it showed before, I can control my CPU fan but not my case fans. Here's what it shows:

Sys Fan: 0 RPM
CPU0 Fan: 948 RPM
Aux0 Fan: 0 RPM
CPU1 Fan: 0 RPM
Aux1 Fan: 0 RPM

Did I plug my fans into the wrong places on the mobo, is SpeedFan not showing "Chassis Fans", or is there something else going on?

Thanks for any help,
7 answers Last reply
More about control case fans speedfan
  1. Hmm I was considering doing this. However, my case fans all have either a speed switch or a dial. Do yours? Possibly, they're trying to draw too much power since they're likely wired to only draw from the molex, but they're controlled by the switches/dials. Or maybe you connected the 3 pin backwards...?
    Check your BIOS and see if they're showing up wherever it shows the temps, cpu fan etc. In my MSI BIOS it's under "H/W Monitor" but yours might be different.
  2. Thanks for the reply. There are no speed switches or dials on my fans. I didn't connect them backwards, I tried and it's not physically possible to plug them in backwards. I checked the BIOS Hardware Monitor and it shows N/A where it would show the RPM's for each Chassis Fan. :(

    Any other ideas?
  3. Hmm well only other thing I can think of is to try one fan at a time, on each of the CHA_FAN pins.
    I've read about something called Q Fan I think, in your mobo's BIOS. Might have to be turned on - not sure what that one does, but it's possible that the fan pins are disabled by a setting.
    That's about all I can think of right now.
  4. Your case fans are probably not speed variable like most fans. The only way you can change their speed is through hardware by a fan controller or a voltage reducing cable.
  5. instead of buying the pins connectors you should have bought a fan controler.
  6. I tried enabling the QFan option in the BIOS, I'm not sure if it's working or not since I can't see the RPM's in Speed Fan or in the BIOS.

    Here are the fans that I got:

    And here's the adapter:

    The fans both say +- 10% for the RPM so they must be speed variable. It sounds like with the fan controller it'll let me control the speed of the fans, but what's preventing me from seeing the RPM's in the BIOS and in Speed Fan? I'm plugging them into the mobo so I'd expect this to work.

  7. :: Bump ::
Ask a new question

Read More

Heatsinks Cases Speedfan Power Supplies Overclocking Product