Mac portables stay on with lid closed -- causes and fixes
Mac portables stay on with lid closed -- causes and fixes
On numerous occasions we've covered an issue where various Mac portables fail to properly sleep when the lid is closed, staying on and active -- generally resulting in excessive heat and an inability to properly function when the screen is re-opened. MacInTouch recently published a number of reader reports on the same issue.
There are a number of causes for this problem, and an equal number of solutions.
In our MacBook Pro special report, we noted that in cases where this occurs, you will notice that the unit's sleep indicator light does not pulse on and off, the fan remains on and the unit extremely hot even though the lid is closed. Battery power also depreciates rapidly.
In a more recent article, we noted that for some MacBooks, the sleep light starts immediately pulsing as soon as the lid is closed, even if the system has not actually fallen asleep yet. This can cause the user to ignore the issue where system stays awake with the lid closed (due to a kernel panic or other problem), resulting in the system draining power and becoming extremely hot.
Some of the fixes we've previously detailed for this issue include:
Check Energy Saver settings Turning off all energy saving options in the Energy Saver pane of System Preferences can resolve this issue for some MacBook Pros.
This can be accomplished by entering the Energy Saver pane of System Preferences, clicking on the "Options" tab, then unchecking all options, including:
- Wake when the modem detects a ring
- Wake for Ethernet Network administrator access
- Restart automatically after a power failure
Check for problems caused by external devices In some cases, errant USB or FireWire devices can cause problems with sudden power-offs. Try disconnecting all such devices and see if the problem persists.
Reset PMU Some users have been able to resolve the problem by performing a PMU reset. Instructions are as linked:
Resetting NVRAM via Open Firmware (PowerPC portables only) A number of users report that resetting NVRAM resolves similar issues. In order to perform this process, hold down the Command, Option, P and R keys at startup until you hear three startup chimes (this resets both PRAM and NVRAM).
Disabling Network activity before sleep Terminating 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.
Other fixes You may want to try some of the workarounds listed in our tutorial "Dealing with Wake-from-sleep issues."
Feedback? Late-breakers@macfixit.com.
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