iMac sleep issues

Unregistered Migrant

Hey,

I have a 27" Apple iMac with an i5 processor and 8GB of RAM running Snow Leopard 10.6.8. I have had it for about a year and a half and for the first 15 months or so it was perfect. However in the last few months I have been having problems with automatic sleep.
When the computer was working correctly if I had set the display to sleep at 5 minutes and the computer to sleep at 15 minutes in energy saver, then if the Mac was idle it would sleep at these times. If however I was say printing a lot of pages or downloading a large file or ripping a DVD, then the computer would not sleep even if the 15 minutes had elapsed but once it had completed its task and 15 minutes had passed, it would sleep. This was great if I was leaving home or going to work as I could rely on my Mac to finish its task and then sleep and so not waste electricity.

So when the problems started, first my Mac would never sleep automatically and this was for a while fixable by simply clicking "restore defaults" in the energy saver settings. Then no matter what it would never sleep unless I set it to sleep manually and now after trying a solution from Apple care (restoring disc permissions in disc utility), the Mac sleeps once the prescribed time has elapsed no matter what I am doing be it listening to iTunes, downloading a file and so on.

In other user accounts this problem also abounds and so doesn't appear to be related to third party software. On the recommendation of an Apple care guy I reinstalled Snow Leopard from disc (the lesser install that does not erase the hard-drive and takes about 45 minutes) and after this the sleep function was working properly. However as soon as I updated the Mac to bring it up to date after the re-install, the problem started again. This gives me the impression that some update from a few months ago is causing this issue.

According to the Apple guy, there is no known solution for this and he tried to sell me a load of horses**t about using third party freeware like caffeine and please sleep to solve the problem. However these solutions are useless unless you are around to ultimately put your Mac to sleep manually and/or turn on/off the third-party software.

This may not seem like a big issue, but when I have my Mac perform many tasks while I am not present, if it stays on indefinitely afterwards, then it is really wasting a lot of electricity.

Has anyone else had this or a similar issue and found a solution? I know I could upgrade to Lion and try that, but if that doesn't work then I will have wasted €24.
Has anyone had any experience with trying to get Apple to replace a computer that is still under Apple Care warranty over a year after purchase as if it continues, my Mac has lost a LOT of its functionality for what I need it to do and I am no longer happy with it.

Thanks.

bennygood

I had a similar problem. My imac would wake itself during the night and in the morning I'd go into the office hear the fans whirring, wasting power. I think it had something to do with the wireless keyboard or mouse. I wish I had a better solution for you but I solved it by upgrading to Lion. I read a few threads on the apple site so you might find a good solution there. A lot of people complained about the computer waking by itself.

Best of luck.

Padgeman

Try using a USB keyboard and mouse for a bit, sometimes Bluetooth peripherals cause problems with sleep on Snow Leopard systems.

Also, post some of the logs from Console.app, it shows what's going on when the system is meant to be going to sleep/waking up.

Something like:

05/11/2011 03:51:42.000 kernel: hibernate image path: /var/vm/sleepimage
05/11/2011 03:51:42.000 kernel: sizeof(IOHibernateImageHeader) == 512
05/11/2011 03:51:42.000 kernel: Opened file /var/vm/sleepimage, size 4294967296, partition base 0x0, maxio 400000 ssd 0
05/11/2011 03:51:42.000 kernel: hibernate image major 14, minor 0, blocksize 512, pollers 5
05/11/2011 03:51:42.000 kernel: hibernate_alloc_pages flags 00000000, gobbling 0 pages
05/11/2011 03:51:42.000 kernel: hibernate_setup(0) took 0 ms
05/11/2011 03:51:42.000 kernel: 00000000 00000020 NVEthernet::setLinkStatus - not Active
05/11/2011 03:52:05.000 kernel: hibernate_page_list_setall start 0xffffff80657e0000, 0xffffff80657ff000
05/11/2011 03:52:05.000 kernel: hibernate_page_list_setall time: 434 ms
05/11/2011 03:52:05.000 kernel: pages 969480, wire 94610, act 408538, inact 16810, spec 2, zf 86898, throt 0, could discard act 188410 inact 157432 purgeable 4084 spec 12696
05/11/2011 03:52:05.000 kernel: hibernate_page_list_setall found pageCount 606858
05/11/2011 03:52:05.000 kernel: IOHibernatePollerOpen, ml_get_interrupts_enabled 0
05/11/2011 03:52:05.000 kernel: IOHibernatePollerOpen(0)
05/11/2011 03:52:05.000 kernel: writing 605614 pages
05/11/2011 03:52:05.000 kernel: encryptStart 2d290
05/11/2011 03:52:05.000 kernel: encryptEnd 3d22830
05/11/2011 03:52:05.000 kernel: image1Size 160960512, encryptStart1 2d290, End1 3d22830
05/11/2011 03:52:05.000 kernel: encryptStart 9981000
05/11/2011 03:52:05.000 kernel: encryptEnd 44c12cc0
05/11/2011 03:52:05.000 kernel: PMStats: Hibernate write took 21984 ms
05/11/2011 03:52:05.000 kernel: all time: 21984 ms, comp bytes: 2480885760 time: 4008 ms 590 Mb/s, crypt bytes: 1056469600 time: 7623 ms 132 Mb/s,
05/11/2011 03:52:05.000 kernel: image 1153510912, uncompressed 2480885760 (605685), compressed 1148796560 (46%), sum1 430f9f22, sum2 46e5e452
05/11/2011 03:52:05.000 kernel: wired_pages_encrypted 38480, wired_pages_clear 54957, dirty_pages_encrypted 512248
05/11/2011 03:52:05.000 kernel: hibernate_write_image done(0)
05/11/2011 03:52:05.000 kernel: sleep

firkin

Unregistered Migrant wrote: »

Hey,

I have a 27" Apple iMac with an i5 processor .....longer happy with it.

Thanks.

Very interesting post.

I have my first mac a year or so now, two of them actually and it's one thing that I can't ever remember working on them. No matter what, they don't go to sleep automatically!

I haven't investigated it too much, but enough to install PleaseSleep. The fact an app like PleaseSleep exists leads me to think Apple need to get their finger out!

Anyway as I have an outbound firewall that lets me see (and block) apps connecting to the internet I noticed that the automatic time update service [ntpd] was constantly trying to make connections every 5 mins.

While trying to investigate that I came across two posts with interesting ideas that may help.
The first said that ntpd may be one reason that the Mac doesn't sleep. So you could try disabling the auto time update feature [go to System Preferences/Date & Time and uncheck "Set date and time automatically"].

The second post [and on my Mac I think this point is related to the first point] the guy said turning off the Firewall logging feature fixed his no sleep issue. For a long time I have noticed in my firewall logs tons and tons of "Stealth Mode connection attempts"

I think those "Stealth Mode connection attempts" are linked to the auto time update issue.

And it seems quite plausible that one or both of those points are causing the mac to stay awake.

So I think there may be something in those two points. I have disabled the auto time update and I'll see how that goes and if that fails I'll try disabling the firewall log.

Hope this is of interest.