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iMac G4 sleep problem

Message #1 - Posted 2007/09/22 - Placebo

I have an iMac G4 that was working perfectly, then I upgraded the hard disk and DVD drive and installed the internal Bluetooth module. After reinstalling OS X, I find that the system will not go to sleep automatically. Putting the system to sleep manually works fine, but if left to go to sleep automatically, it appears to start to go to sleep then seems to hang. It will still respond to pings; I can sort of ssh in -- it takes an incredibly long time but eventually logs me in, but I never get to a prompt. I've reset the PRAM as well as the PMU, but the problem persists. I don't see any clues in system.log as to what's going on when the system tries to sleep. Any idea of how to fix this?

Message #2 - Posted 2007/09/23 - hellman

On Sep 22, 1:30 pm, Placebo wrote:

I have an iMac G4 that was working perfectly, then I upgraded the hard disk and DVD drive and installed the internal Bluetooth module. After reinstalling OS X, I find that the system will not go to sleep automatically. Putting the system to sleep manually works fine

I don't know how to fix your specific problem, but I had a similar problem after upgrading to one of the 10.X OS's. It turned out that Eudora, which was my mail app, was incompatible with the new OS, at least in the sense of Eudora's preventing the Mac from sleeping. Removing Eudora and moving to Apple's Mail app fixed the problem, albeit at a high cost in my time. But, with Eudora on its way out, I needed to move sometime anyway.

Other apps or condiitons also seem to interfere with the Mac sleeping -- and the problem seems at least as serious on my Windows machine. I wonder how many people who think they're getting "energy saving" are not due to problems like this. On the Mac it's particularly easy to not notice that it's awake when it should be sleeping since the screen goes black and the LED glows steady (as opposed to dimming and brightening when it's sleeping). Easy to mistake the two.

Sorry not to be able to help on your specific problem, but hoping something will happen to make sleep harder to mess up.

Message #3 - Posted 2007/09/24 - Placebo

On 2007-09-23 20:50:17 -0700, hellman@stanford.edu said:

Other apps or condiitons also seem to interfere with the Mac sleeping

Thanks for the response. I was just perusing some of the knowledge base articles on Apple's support site, and according to one, hard disk accesses will reset the idle timer, so any application that for whatever reason causes frequent disk accesses will keep the computer awake. That might have been what was going on with Eudora in your case. Like you, I've found that often my systems here often don't go to sleep when left allegedly inactive. Sometimes they do; sometimes they don't.

I looked into my problem a bit more, and it's puzzling. I found when the system hangs, what's happening is that the kernel goes into some weird mode and consumes all of the CPU time. As a temporary workaround, I set the system to never go to sleep automatically. I reinstalled OS X to rule out a software problem. I took the computer apart to see if there was something obviously wrong, but I didn't find anything. Now, I can't get the system to sleep automatically even though the sleep timer is set to just a few minutes.

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