Power Mac G5 dp 1.8GHz fans @ full speed

Discussion in 'PowerPC Macs' started by kbfr08, Jun 25, 2010.

  1. macrumors 6502

    Joined:
    Mar 16, 2007
    #1
    My PCI bay fan is running at full speed no matter what. The temperature sensor reads correctly in OS X, so I don't think it's a bad sensor.

    Is there any way to set the fan speed manually, say in openfirmware?

    It's a 1.8 DP June '04; I've ran ASD 2.5.8 to calibrate and test the mobo, which passed.
     
  2. macrumors 6502a

    Joined:
    Aug 7, 2008
    Location:
    In OSX Snow Leopard / Godalming UK
    #2
    you could try this although i have never tried it
     

    Attached Files:

  3. macrumors 6502a

    bizzle

    Joined:
    Jun 29, 2008
    #3
    smcFanControl does not work on PowerPC Macs.

    Have you tried resetting Open Firmware? Boot into Open Firmware by holding Option-Command-O-F and type 'reset-nvram' and 'reset-all'.
     
  4. macrumors 6502a

    Joined:
    Aug 7, 2008
    Location:
    In OSX Snow Leopard / Godalming UK
    #4
    oh, didn't know that
     
  5. thread starter macrumors 6502

    Joined:
    Mar 16, 2007
    #5
    Yep, i've tried pram resets, nvram resets, everything that I could be reset was reset.
     
  6. macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #6
    Try to disconnect sensor cable and see what happens. If sensor is OK, fan needs to be replaced.
     
  7. thread starter macrumors 6502

    Joined:
    Mar 16, 2007
    #7
    every fan runs at full speed when the sensor cable is disconnected. Anyway, I did a complete rebuild of the G5 and it made no difference either.
    I just installed a quiet fan on the FX5200 using a 12VCC pin on one of the ICs to keep the card from overheating. The large fan is now unplugged until I find a solution.
     
  8. macrumors 601

    OrangeSVTguy

    Joined:
    Sep 16, 2007
    Location:
    Northeastern Ohio
    #8
    Are you running it without the clear air baffle? Try sticking a piece of paper folded up in the far right slot. It's at the bottom right hand corner when you remove the side door. There's a little sensor there that will tell the fans to ramp up if the air baffle is not present. It could also be defective...
     
  9. macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #9
    If air deflector sensor would be defective, red diode at front of logic board should light.
     
  10. macrumors 68020

    toolbox

    Joined:
    Oct 6, 2007
    Location:
    Australia (WA)
    #10
    Exactly, the CPUs' haven't been removed? Some of them need re calibrating if there removed from the logic board.
     
  11. macrumors 601

    OrangeSVTguy

    Joined:
    Sep 16, 2007
    Location:
    Northeastern Ohio
    #11
    Good point! OP, Reboot the G5 with the ASD disc and then run a thermal calibration.
     
  12. macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #12
    Recalibration was done by OP. Besides, as long as CPUs were removed but not swapped between sockets (or replaced), recalibration shouldn't be required.
     
  13. macrumors 68020

    toolbox

    Joined:
    Oct 6, 2007
    Location:
    Australia (WA)
    #13
    I have also had a faulty Thermister also. That was making the fans roar constantly. I replaced that and it settled down
     

Share This Page