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Dave Sag Author

Level 1

18 points

Since upgrading to 10.7.4 the screen savers on my iMac freeze

Since upgrading my iMac to 10.7.4 my screensaver now tends to freeze, requiring a forced reboot of the mac. Stuff does seem to be running under the hood still but I have no way to access it via the UI. I can ssh into the iMac from my other macs and Top claims all is quiet, but I can't actually use the iMac again unless I force a reboot by holding down the power button. This is less than ideal.

It inly happens on my iMac however, and not on my MBP or MacMini.

The workaround for now is for me to disable the screen saver but that's hardly a sustainable solution.

Time Capsule-OTHER, Mac OS X (10.7), new 3TB time capsule & new 27" iMac

Posted on May 13, 2012 7:32 PM

25 replies

Dave Sag Author

Level 1

18 points

Jun 14, 2012 3:10 PM in response to FlyinPhil

After several days my test account has not exhibited the above symptoms, so one solution now is probably to create a new account for myself and migrate over to it. That's quite the PITA however so I decided to experiment some more.

Back in my original account I tried turing off time machine backups as suggested above, and leaving it running overnight with no apps running at all. I also, on a whim, decided to force the rebuild of my spotlight indecies.

I also turned back on the requirement for entering a password to wake up from sleep.

Lo, when I woke up this morning my iMac's screensaver was again frozen, forcing my to ssh into it and reboot.

This eliminates TimeMachine as the culprit (yay)

Now I'm rebuilding spotlight again. ( sudo mdutil -E / if you even need to do that btw,) and have turned the screensaver off, timemachine is still off, and requirement to enter a password to wake from sleep is off. I'll let that run while I'm out at the gym and see what's up when I get home.

If anyone can suggest a cleaner way of killing the screensaver from the terminal that would be great, as forcing a reboot via sudo shutdown -r NOW tends to force quit apps rather than cleanly quitting them.

Dave Sag Author

Level 1

18 points

Jun 15, 2012 5:14 PM in response to Dave Sag

Update: I've been running my iMac now in my usual account with TimeMachine running for over 24 hours now without any issues. I have turned the screen saver off completely and let the iMac 'sleep' the screen after 5 minutes. The requirement for entering a password to wake the screen is off.

I am now going to turn that on and leave it running to see if I can get it to bork again.

Dave Sag Author

Level 1

18 points

Jun 15, 2012 5:40 PM in response to Dave Sag

Well that didn't take long. Since turning back on the security setting to require a password to wake the screen (screensaver is off) it now borks.

When I tap the spacebar the screen wakes up to a glowing black screen. Hitting any key makes an alert tone.

So the solution for me for now is simply to turn off screensaver and turn off the requirement to authenticate to wake the screen from sleep.

This is problematic for me as I am leaving for 5 weeks holiday and would like to leave the mac running but don't fancy giving the people who will be minding my house the ability to mess around with my account on my mac.

Dave Sag Author

Level 1

18 points

Jun 15, 2012 7:30 PM in response to Dave Sag

I recreated a test account, set up similarly to my main account and left it running with the authenticate to unlock screensaver / screen sleep and etc and it works fine. My solution would therefore seem to be to create myself a brand new user account and migrate everything from my old one to my new one.

softwater

Level 5

5,556 points

Jun 15, 2012 7:40 PM in response to Dave Sag

You would be better off finding out what in your current user account is causing the problem, otherwise chances are you'll only recreate the problem through normal use. There's two likely causes/solutions. The first one is a corrupt plist file. To recreate a new plist file do this

In Terminal

rm ~/Library/Preferences/com.apple.screensaver.plist

press 'return' on your keyboard. Restart the computer.

The second likely cause is a software conflict with something else that's runnning only in this account at boot up. To eliminate this:

Remove all items listed in

 > System Preferences > Users & Groups | Login Items

by highlighting them in the list, and clicking the minus '-' button at the bottom of the list (NOTE: not by selecting the checkbox next to each item.)

Restart and test. If the problem is solved, you can add items back to the list one at a time, restarting each time, till you identify the item that recreates the problem.

Dave Sag Author

Level 1

18 points

Jun 16, 2012 6:05 PM in response to softwater

That seems like very good advice. I'll give it a go and let you know how it goes.

My user account on this iMac is the same one I've had for at least 10 years now, which has been progressivly upgraded and updated ever since the original OS X (I've been using a Mac since 1984) and there is all manner of cruft in there, old installs of Mac Ports, and so forth, multiple versions of MySQL, Ruby, I've got old installs of Erlang in there and all manner of things, 99% of which I don't actually use any longer.

Right now I'm using SuperDuper to create a bootable backup of my startup SSD onto a spare FW800 drive and then my plan was to wipe the whole SSD and do a fresh install of Lion and then reinstall the stuff I actually do use one at a time. A lot of that should be fairly painless as long as I am careful - my iTunes lib lives on the 2TB internal HD rather than on the SSD I boot from so that will require the most care, but other than that I can just pull apps from the app store for stuff I've bought there, and reinstall MS Office from the master disks I have here. (I keep all my software rego data in a 1password db fortunately).

But before I embark on that adventure I will try your suggestion re the screensaver plist and eliminating startup apps. Will post an update as I learn more.

Jun 16, 2012 8:50 PM in response to Dave Sag

I hope you can better understand what is causing the issue. I recently got the new 15 inch non-retina display MPB and its starting to do the weird screen saver issue now. I've already gone and one a few of the steps you have and have only noticed the screen saver pop up just before the login menu. Also only things added to the new machine is adobe cs4 master suite and manga studio. Nothing else besides normal iTunes music and iPhotos so I don't think anything I've installed thus far could cause this issue on my machine.

However one thing that might count for something is I've never had this issue on my older MPB (a late 2007) that is running the same OS. Just throwing that out there incase it can help narrow down any leads you're thinking about while on your mission to solve this issue.

Godspeed!

Dave Sag Author

Level 1

18 points

Jun 17, 2012 7:07 PM in response to AlamusPrime

After trying everything else, yesterday I took the drastic step of backing up my internal SSD (using SuperDuper) onto an externam FW800 drive, erasing the SSD and reinstalling Lion from scratch. I've been carefully putting my account back together piece by piece now, rather than just reinstalling from my TimeMachine backup. So far all is working as it should. Screensavers work, security management works etc.

Jun 18, 2012 9:02 AM in response to Dave Sag

Hi,

An update on our situation. Since we only purchased the iMac in April, plus we also purchased Apple Care, and the issue was present form day one and having tried everything support suggested, all the way up to their most senior advisors, I decided to take it into the store last week to see if they could reproduce the issue and fix. Like you may expect they couldn't reproduce the issue. But, I've read of other's who unplugged the unit over night had the issue went away for a few days. So perhaps unplugging the unit has some effect on the power supply that relates to the energy saver? Never the less the store was great, they accepted we would not take the time and trouble to drag a brand new unit to the store if the issue wasn't real. Further our record of attempted fixes with Apple Support was three as a record of our attempts to deal with the issue. Based on having tried all possible standard solutions, and after the store's testing (two days) it was determined it likely could be a hardware issue. Either ram or motherboard. Keeping with Apples commitment to customer satisfaction, after two days of being without the iMac, they agreed to give replace the iMac with a new exact same model etc. Rather than make us be without what my wife needs for work dfor any longer. The assumption was it would either work properly, if not then it would have to be software. It’s now been four days and the problem is gone. Nothing to do with settings etc. as support initially had suggested. It just works like it’s supposed to. However, setting up a new machine and transferring files is more thorough than simply reinstalling the OS, even an erase and install is not the same a setting up a completely new machine.

Anyway, it’s working, we are happy, thanks to the good guys at the Apple Store. That's was totally how it’s supposed to be at Apple.

Buy the way I pointed to this thread as further evidence this matter is not isolated. I guess enough smoke there must be fire. After exhausting all possible ideas on their end. being a brand new unit, I think a replacement was a fair solution.

Hope you extensive efforts resolve your issue.

Cheers,

Phil.

riqiv

Level 1

18 points

Feb 14, 2013 12:09 PM in response to FlyinPhil

I may have a different issue as my screensaver was freezing and the my iMac was so sluggish I suspected a virus.

I took the advice I saw online and deleted:

com.apple.systempreferences.plist.lockfile

in:

HD (Hard Drive/Users/your user name (the little house with your name on it)/Library/Preferences

(Go to: "Go" menu and push "Option Key" to display this "hidden" library.)

In System Pref>Energy Saver I then un-clicked:

"Put hard disks to sleep whenever possible"

My last iMac was almost ruined by having this choice clicked, as I check the computer for email, to write music, to text, for Facebook, etc. several times a day.

It's working fine now, screensaver wakes quickly and computer is no longer sluggish.

Not sure if deleting the "plist.lockfile" had anything to do with the fix, but if it ain't

broke . . . .

I didn't get to the point where I deleted:

/Library/Preferences/com.apple.screensaver.plist

and/or

/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist

but those suggestions seem valid also.

Since upgrading to 10.7.4 the screen savers on my iMac freeze