> From MacFixIt. Simple, REAL simple.
>
>
> Tuesday, January 30 2007 @ 03:00 AM PST
>
> Tutorial: Preventing Portable Mac sleep problems
> Sleep can be temperamental for portable Macs (iBooks, PowerBooks,
> MacBooks, MacBook Pros) with systems sometimes exhibiting one or more
> of these symptoms:
>
> Does not properly go to sleep when the lid is closed, remaining on and
> often resulting in an extremely hot-to-the-touch state with excessive
> fan activity and eventual shutdown.
>
> Wakes from sleep inexplicably while the lid is closed, resulting in
> similar problems as the aforementioned
> Fails to properly wake from sleep, often with a completely black
> screen and no responsiveness
> This problem affects both Intel-based and PowerPC-based Mac portables.
> In many cases, it can be caused by interaction from peripheral
> devices: USB, FireWire, Bluetooth, Displays, even power connection. In
> other cases, power management, NVRAM or software issues are at fault.
> What follows is a listing of the most commonly successful workarounds
> for these issues, along with indications for which problems they are
> most likely to resolve:
>
> Unplug/plug first [Useful for: does not properly go to sleep; wakes
> from sleep while lid is closed; fails to wake from sleep]
>
> Perhaps the most common causes for all sleep problems are problematic
> external USB or FireWire devices. Simply disconnecting all such
> devices before putting a system to sleep can often prevent the
> problems from occurring. Try disconnecting the devices in batches to
> identify a culprit(s).
>
> A few examples of external devices that have caused sleep issues in
> the past:
>
> DYMO label printers can prevent sleep under Mac OS X
> Sleep failure linked to Wacom tablet
> Oxford 911 FireWire sleep problems
> Also, avoid connecting or disconnecting devices, or
> connecting/disconnecting power after your portable Mac has gone to
> sleep. USB devices in particular can trigger a wake from sleep.
>
>
>
> Turn off, toggle settings of Bluetooth devices [Useful for: does not
> properly go to sleep; wakes from sleep while lid is closed]
> It may be beneficial to un-pair and power-off any Bluetooth devices
> associated with Mac portable before putting it to sleep. It appears
> that turning Bluetooth devices on or off while the system is going to
> sleep can trigger a disconnection error message, barring proper sleep.
> Further, you may need to turn off the "Allow Bluetooth devices to wake
> this computer." option in both of its System Preferences locations.
> First, go to the Bluetooth pane of System Preferences and turn this
> option off. Next go to the Keyboard and Mouse pane of System
> Preferences and turn the option off again.
>
> Check for errant internal devices (expansion cards, hard drives, RAM)
> [Useful for: does not properly go to sleep; wakes from sleep while lid
> is closed; fails to wake from sleep]
>
> Some PCI cards, hard drives, or other internal devices can prevent
> proper sleep. Make sure that all internal peripherals are using the
> latest firmware available from the manufacturer, or remove the devices
> in a trial-and-error process to identify the culprit. FireWire 800 PCI
> cards have been notorious in this regard, often preventing deep sleep.
> PCI-based ATA cards, PCMCIA and CardBus cards have also been
> frequently implicated.
>
> If you suspect a faulty hard drive, experiment with a separate startup
> disk. If the sleep issues do not occur with the new drive, consider
> replacing your current startup disk.
>
> Faulty RAM may also be the culprit of your sleep issues, especially if
> other strange issues are occurring. You can sometimes determine if you
> have a "bad" RAM module by using the Apple Hardware Diagnostic CD,
> included with all currently shipping Macintosh models. To use the
> Apple Hardware Test CD, restart your computer while holding down the C
> key on PowerPC-based Macs, or D key on intel-based Macs until the
> "Loading..." icon appears.
>
> You may also want to try removing each RAM module one-by-one and
> checking for persistence of the problem(s).
>
> Turn off AirPort, disconnect from networks before sleep [Useful for:
> does not properly go to sleep]
>
> Disabling Network activity before sleep [Useful for: does not properly
> go to sleep; wakes from sleep while lid is closed; fails to wake from
> sleep]
>
> Related to the above workaround, germinating all network activity --
> in some cases necessitating a power-down of the AirPort card or
> disconnection of an Ethernet cable -- is, in some cases, particularly
> effective at eliminating the "blank screen on wake-up" issue.
>
> In particular, try turning off any built-in AirPort hardware (via the
> AirPort menu item or using Internet Connect, located in
> Applications/Utilities) before putting a portable Mac to sleep.
>
> Manually putting the system to sleep [Useful for: does not properly go
> to sleep]
>
> Putting the system to sleep via the Apple menu or by pressing the
> power button and selecting the sleep option (rather than closing a
> portable Mac's lid) can work to avoid some sleep issues. Make sure
> that the system has properly gone to sleep -- indicated by the gently
> pulsating status light -- before closing the lid.
>
> Turn off all Wake/Other options in Energy Saver [Useful for: does not
> properly go to sleep; wakes from sleep while lid is closed; fails to
> wake from sleep]
>
> Turning off all special automatic sleep options has resolved sleep
> problems for some users. This can be accomplished by entering the
> Energy Saver pane of System Preferences, clicking on the "Show
> Details" button, then the "Options" tab, then un-checking all options,
> including:
>
> Wake when the modem detects a ring
> Wake for Ethernet Network administrator access
> Restart automatically after a power failure
> In some cases you may need to also turn off the "Put the hard disk(s)
> to sleep when possible" option, which is located under the "Sleep" tab
> in the Energy Saver pane of System Preferences.
>
> Quit specific applications [Useful for: does not properly go to sleep]
> Some applications, when active at sleep time, can cause machines to
> either not fall asleep or wake up soon after going to sleep. Though
> it's inconvenient, try quitting all third-party (and potentially some
> Apple) applications before putting your portable Mac to sleep and
> check for persistence of the issue.
>
> As noted in Apple Knowledge Base article #303698, self-refreshing Web
> pages in Safari, songs playing in iTunes, or a movie disc playing in
> DVD Player can all prevent sleep. "Applications can be designed to
> keep the system awake and prevent idle sleep indefinitely. In
> developer lingo, an application may explicitly prevent system sleep by
> calling IORegisterForSystemPower(), and calling IOCancelPowerChange()
> when it receives a power management kIOMessageCanSystemSleep
> notification."
> Set lidwake variable to 0 [Useful for: does not properly go to sleep;
> wakes from sleep while lid is closed]
>
> Setting thelidwake variable to 0 will cause the machine to resist
> waking from sleep when the lid is opened. Instead, you will need to
> press a button on the keyboard or perform another "system event" (such
> as connecting and activating a USB device) in order to wake the
> system.
>
> This can prevent instances of the problem where the system erroneously
> thinks the lid has been opened when it is still closed.
>
> This can be accomplished with the following Terminal command:
>
> sudo pmset lidwake 0
> Deleting power management-related .plist files [Useful for: does not
> properly go to sleep; wakes from sleep while lid is closed; fails to
> wake from sleep]
>
> In some instances, various sleep issues can be resolved by deleting
> the following files:
>
> /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist
> /Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist
> ~/Library/Preferences/com.apple.systemuiserver.plist
> then restarting.
>
> (the tilde [~] indicates your home user directory, i.e.
> /Users/username)
>
> Unfortunately, this fix might not stick, and may require repetition if
> the problem(s) recurs.
>
> Gently close lid -- ensure sleep is taking place [Useful for: does not
> properly go to sleep]
>
> In some cases, carefully closing the lid and ensuring the system has
> actually gone to sleep (indicated by a slowly pulsating light) can
> prevent this issue from occurring.
>
> Turn off safe sleep [Useful for: does not properly go to sleep; fails
> to wake from sleep]
>
> "Safe Sleep" is a function writes the contents of RAM to a hard disk
> buffer. The buffer is then accessed and restored to RAM, creating an
> effect similar to merely putting the system to sleep though it has
> actually been turned off (no power being used).
>
> Mac OS X uses virtual memory data (RAM contents naturally stored on
> disk as part of the virtual memory scheme) to formulate the sleepimage
> file. When the system is put to sleep, Mac OS X culls from physical
> RAM whatever data it cannot replicate from virtual memory and adds it
> to the sleepimage file. As such, if the system is put to sleep
> abruptly or something goes wrong during the write process, sleep can
> fail to properly occur.
>
> If you think safe sleep might be to blame for your regular sleep
> issues, you can disable it by opening the Terminal (located in
> Applications/Utilities) and entering the following command:
>
> sudo pmset -a hibernatemode 0
> then pressing return.
>
> You can then select "Go to Folder" under the "Go" menu in the Finder,
> and enter: /private/var/vm then press return, and drag the file
> sleepimage to the Trash..
>
> In order to re-enable Safe Sleep, use the command:
>
> sudo pmset -a hibernatemode 3
> in the Terminal.
>
> Reset NVRAM [Useful for: does not properly go to sleep; wakes from
> sleep while lid is closed; fails to wake from sleep]
>
> A number of users report that resetting NVRAM resolves wake-from-sleep
> issues. In order to perform this process, shut down your Mac, then
> start it back up while immediately holding the following keys:
> Command, Option, P and R. Hold the keys down until the computer
> restarts and you hear the startup sound for the third time.
>
> Clear caches [Useful for: does not properly go to sleep; wakes from
> sleep while lid is closed; fails to wake from sleep]
>
> Though it's a clich