iBook G4 -- won't wake up

Discussion in 'PowerPC Macs' started by cummings78, Aug 4, 2008.

  1. cummings78 macrumors newbie

    Aug 4, 2008
    Hello, and apologies if this question has long ago been asked and answered... I have an iBook G4 running OS 10.4.11, that has just had the hard drive replaced. When the computer goes to sleep it will not wake up, an in order to restart it I have to disconnect the power adapter and close it. I have it set to put the computer to sleep never, but eventually the computer--or at least the display--will sleep and not wake up without a restart. Is this a common problem, and is there any fix I should try? Any suggestions are welcome.
  2. cMacSW macrumors regular

    Mar 20, 2006
    What type of Hard Drive did you replace with?
  3. techound1 macrumors 68000


    Mar 3, 2006
    reset the pmu

    A computer's PMU (Power Management Unit) is relevant to:
    sleep/wake issues
    battery issues (such as not charging at all)
    power-on issues
    port issues (USB/FireWire ports appear dead).

    The Power Manager is an integrated circuit (computer chip) that is usually on the logic board of the PowerBook and iBook. As the name implies, it is responsible for power management of the computer. It controls backlighting, hard disk spin down, sleep and wake, some charging aspects, trackpad control, and some input/output as it relates to the computer sleeping.

    Over time, the settings in the Power Manager may become unusable, which can result in operational anomalies with the computer. Examples include not turning on, not waking from sleep, not charging the battery, or not seeing the AC Adapter, among others.

    Performing a PMU reset returns the hardware, including NVRAM, to default settings and forces the computer to shut down.

    1. If the computer is on, turn it off.
    2. Reset the power manager by simultaneously pressing and then releasing Shift-Control-Option-Power on the keyboard. Do not press the fn (Function) key while using this combination of keystrokes.
    3. Wait 5 seconds.
    4. Press the Power button to restart the computer.

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