Tuesday, November 6, 2012

Mac Freezes Waking From Screen Saver

Since updating to Mountain Lion, or perhaps later versions of Lion, I’ve seen a bug where the Mac freezes when coming out of the screen saver. There’s no way to unlock the screen. It has not actually kernel panicked, as applications continue to run and I can ssh in, however the Mac is essentially unusable until it’s been shut down—via ssh, as that’s a bit cleaner than using the power button. This problem didn’t occur every time I used the screen saver, but at its peak it was happening nearly once a day.

I tried different screen savers, but that didn’t help. What did help was disabling the screen saver entirely (setting it to “Start after: Never”) and instead using Energy Saver’s “Display sleep” setting to lock the screen. (I had been using this before, but with Energy Saver set to kick in after a longer delay than the screen saver.) Using these settings for nearly a month, the problem has not recurred.

However, I’m still seeing various display waking problems that have been happening since Lion. Sometimes both screens remain blank (but with the backlight on) until after I’ve entered my password and pressed Return. Other times, the internal display wakes but the external one doesn’t. In that situation, the workaround is to unplug and replug the display. The window positions get all messed up, then Moom fixes them automatically.

All of this is to say that I still think that 10.6.8 was the pinnacle of Mac OS X reliability.

Tags: , , , ,

8 Comments

"All of this is to say that I still think that 10.6.8 was the pinnacle of Mac OS X reliability."

I enjoy its well-architected usability, polish, and stability every day on multiple machines.

(It's really not just stability that fell into disrepair beginning with the loveliness of 'back to the mac' Lion. I still think Snowy is the pinnacle of GTD in OS X on multiple fronts.)

My favorite wake-from-sleep bug so far: make your Mac ask for your password on wake, then activate Mission Control; wait for it to sleep. Upon wakeup you'll have your desktop picture on a linen background, and on top of it a window asking for your password... but you can't type in that window! You're stuck in that kind-of Mission Control mode.

It's frustrating, until you realize that the button far at the bottom to return to the login screen works, and from there you can move on.

Lion (haven't upgraded beyond) really messed up my MBA's sleep/wake as well. It's a distant memory now, but one of the joys of the Air was it fading quickly to life when the lid was opened.

After upgrading to Lion, it's now a much more stuttered and unreliable process. The probability of the backlight not coming on when the machine wakes gradually increases through a month or so until I do an SMC reset. Even if the screen works correctly, it can take anywhere from just a few seconds to half a minute for the machine to become usable after opening.

At one point I found and tried a pmset command to disable deep sleep that may (or may not have?) helped for a while. I've been sorely tempted to go back to Snow Leopard but would miss having FileVault2 on my laptop. Has anyone had better experiences with Mountain Leather?

Dan Kletter suggests deleting the file:

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

About the same here: since I upgraded to Lion, I saw such freezes when reactivating from screen saver. My solution is to put directly to sleep or, for shorter breaks, use the prevent-the-screen-saver-from-occurring hot corner (come to think of it, maybe I should have disabled the screen saver entirely) and manually turning off the display (I use a Mac pro).

I hope this fixes this issue:
http://support.apple.com/kb/DL1609

Can anybody confirm whether it does or not?

[...] is. I’m not sure what’s behind this, although people seemed to agree last week when I noted Snow Leopard’s [...]

I found that if you click on 'Switch User' and then login as the account you were just working from that you are returned to the environment you were locked out of. HTH.

Stay up-to-date by subscribing to the Comments RSS Feed for this post.

Leave a Comment