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Display Sleep not working

I'm using Mountain Lion on two iMacs.

On both 'System Preferences' > 'Energy Saver' > 'Display Sleep' does no longer work reliably (compared with Snow Leopard or Lion).

When I close all apps and set the Display Sleep time to "1 min." (minimum) and wait... in the majority of cases the display stays ON!

What's the reason? How can this be fixed?

Many thanks!

Posted on Nov 22, 2012 2:22 AM

Reply
13 replies

Nov 22, 2012 2:28 AM in response to coxorange

does the Mac sleeps itself?

have you tried to reboot your Mac as it might be that some apps are keeping it awake?

try to set up hot corners

System preferences > Mission Control > Hot corners > and set one of corners to Put display to sleep and see if it works when you move your mouse cursor to that corner.

Nov 22, 2012 4:06 AM in response to Munas

Many thanks for your answer!

After rebooting Display Sleep worked.

Using the Hot corner method also did it.

But after working awhile using some apps (no exotic ones) Display Sleep no longer works

(though even in this situation the Hot corner method works - but I don't like using Hot corners).

How can I find out what keeps my Macs from sleeping?

Nov 22, 2012 7:49 AM in response to coxorange

when you see that your mac refuses to sleep, run terminal and enter the command

pmset -g assertions

normally (if nothing is stopping the Mac from going to sleep) the result should look like


Assertion status system-wide:
PreventUserIdleDisplaySleep 0
PreventSystemSleep 0
PreventUserIdleSystemSleep 0
ExternalMedia 0
UserIsActive 0
ApplePushServiceTask 0
BackgroundTask 0


If you have 1 instead of 0 somewhere, the line bellow might explain the reason of it.

Nov 23, 2012 7:33 PM in response to Munas

Thanks for this tip!


When running terminal with pmset -g assertions I get the following result:


24/11/2012 03:28:47 GMT

Assertion status system-wide:

PreventUserIdleDisplaySleep 1

CPUBoundAssertion 0

PreventSystemSleep 0

PreventUserIdleSystemSleep 0

ExternalMedia 1

DisableLowPowerBatteryWarnings 0

UserIsActive 0

ApplePushServiceTask 0

BackgroundTask 1



Listed by owning process:

pid 175(helpd): [0x0000000c00000134] 40:46:13 BackgroundTask named: "com.apple.helpd.sdmbuilding"

pid 17(powerd): [0x000000050000020e] 37:24:19 PreventUserIdleDisplaySleep named: "com.apple.powermanagement.delayDisplayOff"

pid 17(powerd): [0x00000009000001f5] 37:45:27 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"



Kernel Assertions: 0x0132

* Kernel Assertion ID = 500

Created At = 01/01/1970 01:02:39 GMT+

Modified At = 22/11/2012 10:45:20 GMT

Owner ID = 0xffffff801bab9000

Level = 255

Assertions Set = None (4)



* Kernel Assertion ID = 501

Created At = 01/01/1970 01:02:40 GMT+

Modified At = 22/11/2012 10:45:21 GMT

Owner ID = 0xffffff801baca000

Level = 255

Assertions Set = None (4)



* Kernel Assertion ID = 814

Created At = 24/11/2012 03:39:57 GMT

Modified At = 01/01/1970 01:00:00 GMT+

Owner ID = 0xffffff801bb89b00

Level = 255

Assertions Set = None (128)


What's my problem and how can I fix it?

Nov 23, 2012 7:38 PM in response to coxorange

these 3 processes stop your mac from sleeping:

pid 175(helpd): [0x0000000c00000134] 40:46:13 BackgroundTask named: "com.apple.helpd.sdmbuilding"

pid 17(powerd): [0x000000050000020e] 37:24:19 PreventUserIdleDisplaySleep named: "com.apple.powermanagement.delayDisplayOff"

pid 17(powerd): [0x00000009000001f5] 37:45:27 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"

If helpd will not disappear after some time try to kill it in terminal. Additionally, it seams that you have connected external media that prevents mac from sleeping. have you connected external disk or any other device?

Nov 24, 2012 3:53 AM in response to Munas

Munas wrote:


If helpd will not disappear after some time try to kill it in terminal.


I'm afraid this is a re-occurring problem, so I would rather avoid the cause than always kill that process. How can I find out what causes this problem? After rebooting the problem doesn't exist.



Additionally, it seams that you have connected external media that prevents mac from sleeping. have you connected external disk or any other device?


I have connected some external USB devices (hubs, web cams, DVD drive, backup drive for Time Machine), BUT all this had been connected already when I was using Snow Leo or Lion - and these devices NEVER prevented the display from sleeping - so I would consider them as "innocent".


Another thing I don't understand: When these 3 processes are so important to prevent the display from sleeping (why by the way?), why is it then possible to achieve that sleep via hot corners...?


Thanks again for your help!

Nov 24, 2012 5:08 AM in response to coxorange

It might be that these external devices prevented your Mac from sleep just that moment when you were running the command in terminal and it is normal if ones were doing something.

run this command few times more at different tymes of day to see are these messages permanent....

I have had problem with helpd and solved it by removing from launch, however later I found that I am unable to use help files and added it again. Surprise, but the problem did not reappeared. Lets see are the other guys powerd are sitting there permanently.

Additionally, how it is hard to define which processes causing which problems you may run pmset -g assertions again and see the status, ten disconnect external media and after few minutes run it again and check what is changed in status...

Nov 25, 2012 5:31 AM in response to Munas

Munas wrote:


It might be that these external devices prevented your Mac from sleep just that moment when you were running the command in terminal and it is normal if ones were doing something.

run this command few times more at different tymes of day to see are these messages permanent....


I've tried it many times (haven't restarted since the previous post). Mostly it was the same - never better - in the meantime it got even worse (4th: AppleFileServer!):


25/11/2012 12:51:39 GMT

Assertion status system-wide:

PreventUserIdleDisplaySleep 1

CPUBoundAssertion 0

PreventSystemSleep 1

PreventUserIdleSystemSleep 0

ExternalMedia 1

DisableLowPowerBatteryWarnings 0

UserIsActive 0

ApplePushServiceTask 0

BackgroundTask 1



Listed by owning process:

pid 7997(helpd): [0x0000000c00000aa9] 00:15:22 BackgroundTask named: "com.apple.helpd.sdmbuilding"

pid 17(powerd): [0x000000050000020e] 70:47:11 PreventUserIdleDisplaySleep named: "com.apple.powermanagement.delayDisplayOff"

pid 17(powerd): [0x0000000900000663] 16:57:32 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"

pid 383(AppleFileServer): [0x0000000800000ab4] 00:03:13 DenySystemSleep named: "com.apple.AppleFileServer"



Kernel Assertions: 0x0004

* Kernel Assertion ID = 500

Created At = 01/01/1970 01:02:39 GMT+

Modified At = 22/11/2012 10:45:20 GMT

Owner ID = 0xffffff801bab9000

Level = 255

Assertions Set = None (4)



* Kernel Assertion ID = 501

Created At = 01/01/1970 01:02:40 GMT+

Modified At = 22/11/2012 10:45:21 GMT

Owner ID = 0xffffff801baca000

Level = 255

Assertions Set = None (4)


You wrote:


I have had problem with helpd and solved it by removing from launch, however later I found that I am unable to use help files and added it again.

How would I do this?

Thanks.

Nov 25, 2012 6:56 AM in response to coxorange

In addition to the above:


Now I restarted and immediately ran terminal with "pmset -g assertions":


25/11/2012 14:49:44 GMT

Assertion status system-wide:

PreventUserIdleDisplaySleep 0

PreventSystemSleep 0

PreventUserIdleSystemSleep 0

ExternalMedia 1

DisableLowPowerBatteryWarnings 0

UserIsActive 0

ApplePushServiceTask 0

BackgroundTask 1



Listed by owning process:

pid 18(powerd): [0x000000090000012c] 00:05:33 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"

pid 173(helpd): [0x0000000c00000137] 00:05:13 BackgroundTask named: "com.apple.helpd.sdmbuilding"



Kernel Assertions: 0x0004

* Kernel Assertion ID = 500

Created At = 01/01/1970 01:02:49 GMT+

Modified At = 25/11/2012 14:46:38 GMT

Owner ID = 0xffffff801f711000

Level = 255

Assertions Set = None (4)



* Kernel Assertion ID = 501

Created At = 01/01/1970 01:02:49 GMT+

Modified At = 25/11/2012 14:46:42 GMT

Owner ID = 0xffffff801f712000

Level = 255

Assertions Set = None (4)


Even though ExternalMedia and BackgroundTask were set to "1" the display went to sleep after a minute!

Does this help...?

Nov 25, 2012 7:24 AM in response to coxorange

It is good to know that your display has no insomnia anymore.

One more think to check: does you Mac sleep?


the command to remove helpd from starting is (in terminal)

launchctl unload -w /System/Library/LaunchAgents/com.apple.helpd.plist


However, since the screen started to sleep I would not run this command and if it stops one day I would run the same command and check what are the differences in results.

Nov 25, 2012 5:04 PM in response to Munas

Unfortunately the problem is back again:


Assertion status system-wide:

PreventUserIdleDisplaySleep 1

CPUBoundAssertion 0

PreventSystemSleep 0

PreventUserIdleSystemSleep 0

ExternalMedia 1

DisableLowPowerBatteryWarnings 0

UserIsActive 0

ApplePushServiceTask 0

BackgroundTask 1



Listed by owning process:

pid 18(powerd): [0x0000000500000165] 09:58:47 PreventUserIdleDisplaySleep named: "com.apple.powermanagement.delayDisplayOff"

pid 18(powerd): [0x00000009000001f2] 03:36:36 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"

pid 173(helpd): [0x0000000c00000137] 10:12:07 BackgroundTask named: "com.apple.helpd.sdmbuilding"



Kernel Assertions: 0x0004

* Kernel Assertion ID = 500

Created At = 01/01/1970 01:02:49 GMT+

Modified At = 25/11/2012 14:46:38 GMT

Owner ID = 0xffffff801f711000

Level = 255

Assertions Set = None (4)



* Kernel Assertion ID = 501

Created At = 01/01/1970 01:02:49 GMT+

Modified At = 25/11/2012 14:46:42 GMT

Owner ID = 0xffffff801f712000

Level = 255

Assertions Set = None (4)


You asked:


does you Mac sleep?


You mean the complete sleep? Yes, but if I want this, I switch it manually.


the command to remove helpd from starting is (in terminal)

launchctl unload -w /System/Library/LaunchAgents/com.apple.helpd.plist


... and what would I have to enter to reactivate helpd?


Thanks.


BTW It seems no one else here has this problem. (And I have it on both of my Macs.)

Nov 25, 2012 5:23 PM in response to coxorange

replace unload with load to reactivate it.

and

launchctl start /System/Library/LaunchAgents/com.apple.helpd

to start it.


P.S. it seams that helpd stays forever in your tasks.

P.P.S. There are applications that prevent display sleep i.e. some video apps when you watch video. Do you have this kind of app running. Check the light indicator at your Dock.

Display Sleep not working

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