Dual G5 random shutdowns - PMU?

Discussion in 'PowerPC Macs' started by decksnap, Sep 8, 2006.

  1. macrumors 68040

    decksnap

    Joined:
    Apr 11, 2003
    #1
    My system has randomly shut down twice now in the last two days. Dual G5 2.3. I checked the console log, which I know very little about, and it said this:

    localhost kernel[0]: ApplePMU::pMU forced shutdown, cause = -122

    Two questions-

    what's the -122 code mean?

    Do you think resetting the PMU would be the solution to this?
     
  2. thread starter macrumors 68040

    decksnap

    Joined:
    Apr 11, 2003
    #2
    Interestingly, the Apple support pages say my system doesn't even have a PMU, but rather an 'SMU'. So why does the console say PMU???

    link
     
  3. Guest

    iGary

    Joined:
    May 26, 2004
    Location:
    Randy's House
    #3
    It is normally a small button under the RAM.

    Also try holding CMD-OPT-O-F on startup and then enter reset-all.
     
  4. macrumors regular

    Joined:
    Mar 8, 2005
    Location:
    Hanover PA
    #4
    Can you give us an update? Did it solve your problem?
     
  5. thread starter macrumors 68040

    decksnap

    Joined:
    Apr 11, 2003
    #5
    Nobody's answered either of my questions so I haven't acted on it. Thanks for the bump though. Very curious to see a list of the error codes. And why console says PMU when I have an SMU.
     
  6. macrumors newbie

    Joined:
    Oct 2, 2006
    Location:
    San Francisco, CA
    #6
    G5 dual random shutdown

    I had the same problem, but only after updating to OS 10.4.7 from 10.4.5. After several days of extreme frustration, I reinstalled 10.4.5, and all was well.

    Today I just tried updating to 10.4.8. Same problem is now happening:

    localhost kernel[0]: ApplePMU::pMU forced shutdown, cause = -122

    Anybody know what could be going on?
     
  7. thread starter macrumors 68040

    decksnap

    Joined:
    Apr 11, 2003
    #7
    So you've isolated it to software?

    I''m on 10.4.7.

    I've tried resetting the SMU, resetting the pram. Got a new surge protector.

    I've basically been able to reproduce the problem by opening two or three quicktimes at the same time, and/or adding iTunes into the mix. I will see what happens when I upgrade to 10.8.
     
  8. macrumors newbie

    Joined:
    May 31, 2006
    #8
    http://www.xlr8yourmac.com/systems/Dual_Core_G5_Shutdowns.html

    check the console crash log and look for a error report (-122)

    google that along with "random shutdowns G5"

    the problem is like an epidemic.

    extrodinarily random and from what ive learned, no way to ensure a solid fix.

    my g5 is getting the CPU and power supply replaced, first time after 6months... i havent even finished payments on this (2nd gen dual 2.5) G5, and im just a kid who relys on his computer to make art and music on... i cant afford a new one, and now at worst ill be using a defective machine that has a trip to the emegency room every so often at MY expense. and if not that, ill just use it constantly fearing it'll crash on me. im sad about this.

    but i dont have faith its going to be reliable still...

    theres still the logic board, cooling system, video card...

    i noticed this problem is occuring with the macbook pros too.
     
  9. macrumors newbie

    Joined:
    May 31, 2006
    #9
    http://www.gibbilicious.com/gibbilicious/2006/02/troubleshooting_the_mysterious.html

    that link explained the error code, -or what could be said for it at least.
     
  10. thread starter macrumors 68040

    decksnap

    Joined:
    Apr 11, 2003
    #10
  11. macrumors newbie

    Joined:
    Nov 22, 2010
    #11
    ApplePMU::pMU forced shutdown, cause = -122 A solution?

    Guys, I've had ApplePMU::pMU forced shutdown, cause = -122 for years. I tried everything without success so far...
    Today, out of the blue, I seem to have found a solution. The culprit seems to be a faulty clock and Pram battery. Even if the internal clock functions regularly, a lower voltage from the battery could cause all kinds of strange behaviour. I replaced the battery today and was able to run 5 youtube videos simultaneously, with processor speed to automatic and did not have any shutdown. This morning playing a single video would cause the shutdown...

    So, I don't want to raise false hopes but replacing he battery is definitely worth a try!


    Cheers


    Mr Michele From Italy.
     
  12. macrumors newbie

    Joined:
    Dec 10, 2010
    #12
    So it has been several weeks since you came across this possible fix - have you had the shutdown since replacing the battery?
     
  13. macrumors newbie

    Joined:
    Nov 22, 2010
    #13
    Yes. I am afraid I had a few shutdown but definitely less. I also introduced another change: Instead of disconnecting the main power source from the computer with a switch, I always keep the mac connected, even when It's switched off.

    This seems to "do some good".

    Im am sorry I can't say the solution is 100% effective thought.
     

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