4 Replies Latest reply on Sep 15, 2012 10:07 AM by Osh Moz

    DH77EB fan problem

    Osh Moz



      I just purchased DH77EB motherboard and updated the BIOS to the latest version (89). I noticed that I get no reading regarding the CPU fan speed in the BIOS display. Since the fan was working I installed Windows 7 64bit, and I tried to get a fan speed reading from inside the OS but various fan speed applications did not give any reading.

      My second problem is that a chassis fan that I connected to the front fan header is not rotating at all. Any ideas? I did not change the default settings in the BIOS.


      Thanks in advance,


        • 1. Re: DH77EB fan problem

          try plugging the front fan into another fan header and see if it works.

          What CPU heatsink\fan are you running? I had an Arctic Cooler Freezer 7, and it wouldn't show the RPM until the fan spun past a certain RPM (1000ish)

          With the stock intel heatsink\fan it shows the RPM no problem.

          1 of 1 people found this helpful
          • 2. Re: DH77EB fan problem
            Osh Moz

            Thank you for your quick reply.


            Actually I also have Arctic Cooler Freezer Rev 2, but I cannot get it to show the RPM. I'm currently stressing my CPU with Prime95 and I cannot get the CPU above 58c or get any reading from the fan. Do you by any chance remember the temperature needed to raise the RPM of the fan and get a reading?


            I will also trying changing fan header later and let you know about the results.

            • 3. Re: DH77EB fan problem

              Those are very low temps. In the bios you canset the cpu fan to 50% min duty cycle, that should bring the fan rpm up

              1 of 1 people found this helpful
              • 4. Re: DH77EB fan problem
                Osh Moz

                You were right again. I raised the min duty cycle to 50% and the fan indeed started to spin faster and I got a reading for fan speed in the BIOS.


                The solution for the chassis fan is quite embarrassing. I had a resistor on an extension cable attached to the fan (Zalman), It came this way from the factory so I never thought about it. I just removed the extension cable with the resistor and the fan started spinning without a problem. I have no idea what's the point with the resistor.


                Thanks for everything.