lazerpouf

Q: Power Mac G5 Dual Core gets hot and fans run slow

Hello

 

I have a Power Mac G5 (Late 2005) Dual Core that has fan problems. The temperatures get high and the fans barely spin up. The CPU fans sit at 499 and 515 rpm and when playing Minecraft they go to about 600 rpm and the CPU gets up to 151F. I have ran Apple Hardware Test and it still doesn't work. It is running Mac OS 10.5 and has 6 GB of RAM and has a 500GB hard drive. I have:

  • Reset PRAM
  • Re-installed Mac OS X
  • Replaced Hard Drive
  • Cleaned dust
  • Ran AHT
  • And reset the SMU
  • Tried editing AppleFan.kext

iStat pro says the fans spin about:

CPU A intake: 499 rpm

CPU A exhaust: 515 rpm

CPU B intake: 499 rpm

CPU B exhaust: 515 rpm

Backside: 1000 rpm

Slots: 1500 rpm

drive bay: 1000 rpm

 

Is this normal? Do they always spin slow or is there any other things I can do or software to download?

PowerMac, Mac OS X (10.5)

Posted on Feb 15, 2016 4:00 PM

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Q: Power Mac G5 Dual Core gets hot and fans run slow

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  • by lazerpouf,

    lazerpouf lazerpouf Feb 18, 2016 12:03 PM in response to BDAqua
    Level 1 (0 points)
    Feb 18, 2016 12:03 PM in response to BDAqua

    I downloaded it, but I have no idea what it does, how to use it, or what I should do with it?

  • by BDAqua,

    BDAqua BDAqua Feb 18, 2016 12:35 PM in response to lazerpouf
    Level 10 (123,775 points)
    Feb 18, 2016 12:35 PM in response to lazerpouf

    After you uncompress it just double click on the file dnetc on it, it'll open a configuration menu in Terminal to set it up & run it.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 18, 2016 12:36 PM in response to lazerpouf
    Level 5 (7,714 points)
    Notebooks
    Feb 18, 2016 12:36 PM in response to lazerpouf

    We do not know what figure the CPU has as it's max temperature 157ºF seems high but we do not know that for a fact - Apple does not give a hard figure (not even in the SS). [Please correct me if I am wrong BDAqua]. The Mac Rumours forum link has a user who claims to have got this model up to 205ºF

    IBM may have documentation, however Apple may have ordered a spec that differs from ones sold to other makers so getting accurate info is hard.

    https://en.wikipedia.org/wiki/PowerPC_970

     

    Thermal compound transfers heat from the CPU to the heat sink. As it ages it can dry out producing gaps or areas with poor heat transfer. Replacing it can cause better heat dissipation from the CPU to the heat sink.

     

    I'm not suggesting the thermal compound replacement because of the readings you have but simply because it is old. Expansion & contraction over 10 years can contribute to cause a breakdown of the joint with the thermal compound.

    Your fans should actually run faster if you have a poor junction between the CPU & the heat sink because the CPU would register the temp as being too high & should request more cooling. The CPU may even shutdown if there is not enough cooling.

     

    I will look for those old temp figures at the weekend but I currently can't access them.

  • by lazerpouf,

    lazerpouf lazerpouf Feb 18, 2016 1:02 PM in response to BDAqua
    Level 1 (0 points)
    Feb 18, 2016 1:02 PM in response to BDAqua

    Hi

    What do I use this utility for? What does it do? What should I use it for?

  • by lazerpouf,

    lazerpouf lazerpouf Feb 18, 2016 1:08 PM in response to Drew Reece
    Level 1 (0 points)
    Feb 18, 2016 1:08 PM in response to Drew Reece

    OK, thank you.

     

    I am trying to get the fans to spin up faster but could it be a hardware problem?

    499/515/800 rpm seems slow for a hot G5 CPU. Any way to speed them up?

  • by BDAqua,

    BDAqua BDAqua Feb 18, 2016 1:26 PM in response to lazerpouf
    Level 10 (123,775 points)
    Feb 18, 2016 1:26 PM in response to lazerpouf

    It'll tax all your CPUs to the max so we can see if the fans speed up or not.

    dnetcCPUusage.gif

  • by lazerpouf,

    lazerpouf lazerpouf Feb 18, 2016 1:40 PM in response to BDAqua
    Level 1 (0 points)
    Feb 18, 2016 1:40 PM in response to BDAqua

    How do I make it tax the CPUs?

    I just opened up the software, there is 100% CPU. CPU A core 1/2 is at 157/158ºF and the fans are not spinning up!

    What does this program do?

  • by Drew Reece,

    Drew Reece Drew Reece Feb 18, 2016 1:40 PM in response to lazerpouf
    Level 5 (7,714 points)
    Notebooks
    Feb 18, 2016 1:40 PM in response to lazerpouf

    lazerpouf wrote:

     

    OK, thank you.

     

    I am trying to get the fans to spin up faster but could it be a hardware problem?

    499/515/800 rpm seems slow for a hot G5 CPU. Any way to speed them up?

    Heat your room. The SS says 77ºF/25ºC is the max room temp for thermal calibration, get close to that temp in the room.

    Higher ambient air = less cooling.

    Less cooling = more air needed over the heat sinks to maintain the same temp.

    Load the CPU's to max (in high performance mode) & leave them running for a long time.

     

    You have seen these fans spin at max when you did the thermal calibration - you said it was loud.

    lazerpouf wrote:

    No, they do not spin up when at the Startup Manager.

    But they do spin up to max when in ASD or Single-User Mode.

    (It's really loud)

    They are spinning fast when at the Startup manager.

    Your hardware is not incapable of spinning the fans at high rates - it seems like it just doesn't feel like it is necessary when the OS is running.

    The SS mentions that fan management is not used when no OS is running - it should run fast at that point as a precaution but you don't have a way to see the fan speed when running ASD.

  • by lazerpouf,

    lazerpouf lazerpouf Feb 18, 2016 1:47 PM in response to Drew Reece
    Level 1 (0 points)
    Feb 18, 2016 1:47 PM in response to Drew Reece

    I am currently running the software that BDAqua suggested and the fans are running at almost 900 rpm. This software will probably be running a long time.

    However, when starting the computer before the login window loads, the fans spin fast (~1700 rpm maybe) and then spin down when the login window loads.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 18, 2016 1:56 PM in response to lazerpouf
    Level 5 (7,714 points)
    Notebooks
    Feb 18, 2016 1:56 PM in response to lazerpouf

    lazerpouf wrote:

     

    However, when starting the computer before the login window loads, the fans spin fast (~1700 rpm maybe) and then spin down when the login window loads.

    That fits with my experience, seems normal.

  • by BDAqua,

    BDAqua BDAqua Feb 18, 2016 1:58 PM in response to lazerpouf
    Level 10 (123,775 points)
    Feb 18, 2016 1:58 PM in response to lazerpouf

    Is it running OGR or dnetc? Both are option there.

     

    See if the temp goes to 170°F if the fans speed up.

  • by lazerpouf,

    lazerpouf lazerpouf Feb 18, 2016 2:00 PM in response to BDAqua
    Level 1 (0 points)
    Feb 18, 2016 2:00 PM in response to BDAqua

    It is dnetc.

    The cpu got to 169ºF and the fans were almost 900 rpm

  • by BDAqua,

    BDAqua BDAqua Feb 18, 2016 2:28 PM in response to lazerpouf
    Level 10 (123,775 points)
    Feb 18, 2016 2:28 PM in response to lazerpouf

    So, the fans didn't speed up much or at all?

     

    When you edited the fans.kext plist did you make the permission correct again?

  • by lazerpouf,

    lazerpouf lazerpouf Feb 18, 2016 2:33 PM in response to BDAqua
    Level 1 (0 points)
    Feb 18, 2016 2:33 PM in response to BDAqua

    Hi

    The maximum the fans ever went up to is ~900 rpm. The Drive Bay, Slots Intake and Backside fans all revolve at the same speed, and they don't change.

    Since I replaced the hard drive and installed a "Erease and install" of OS X Leopard, the changes to AppleFan.kext have been set to default. Is it okay to edit it again? (To make the fans spin faster)

  • by BDAqua,

    BDAqua BDAqua Feb 18, 2016 2:41 PM in response to lazerpouf
    Level 10 (123,775 points)
    Feb 18, 2016 2:41 PM in response to lazerpouf

    Hmmmm, seems it's not using that kext or the PowerMac11_2_ThermalProfile.kext, but I guess it wouldn't hurt to try an edit again.

     

    In Terminal using kextstat, does it show PowerMac11_2_ThermalProfile.kext loaded?

     

    Or in Sys Prefs>More Info>Software>Extensions?

     

    PowerMac11_2_ThermalProfile:

     

      Version:    1.8.6

      Last Modified:    10/10/07 07:04

      Get Info String:    PowerMac11_2_ThermalProfile version 1.8.6, Copyright 2004-2007 Apple Inc.

      Location:    /System/Library/Extensions/AppleMacRISC4PE.kext/Contents/PlugIns/PowerMac11_2_T hermalProfile.kext

      kext Version:    1.8.6f1

      Load Address:    0x6c254000

      Valid:    Yes

      Authentic:    Yes

      Dependencies:    Satisfied

      Integrity:    Correct

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