I've been having this problem that nobody seems to know the answer. Occasionally when the Mac sleeps for a long time (i.e. over 30 minutes) it goes into a coma and won't wake up. When I press a key to wake it up it makes an attempt, then poops out after about a half second. If I push the power button at this point the light lights up (while I'm pressing down) but no fan spinup. I have to unplug the computer just to get it to start up again.
My question is actually this: it seems, and maybe I'm imagining it, but it seems like when I leave the plug out for, say, overnight the problem does not reoccur for some time (like a week or so). But if I just unplug the thing for 15 seconds, it could occur the very next day. So what difference is there between unplugging for hours versus seconds? And does info lead anyone to suggest an answer to fixing this problem?
If your Mac happily goes to sleep but won't wake up--Hold down the power switch to force-reboot your machine and get it running again. Don't worry-your Mac isn't narcoleptic. Its Open Firmware system or NVRAM (nonvolatile RAM) is likely corrupt, and your Mac can't remember how to wake up. Restart your Mac and immediately hold down the Command-Option-O-F key combo until you see a somewhat intimidating command-line display that ends with the Open Fimware prompt. Type the following lines: reset-nvram press Return on keyboard set-defaults press Return reset-all press Return Your Mac will reboot. Once it's running, put it back to sleep to test. If the problem recurs your Energy Saver preferences may be the culprit. Delete the com.apple.PowerManagement.plist file (go to Finder/Hard drive/Library/Preferences/SystemConfiguration)--don't worry, your Mac will regenerate a new one--and then restart to see if that rights the wrong. Still did'nt work? Might be time to call AppleCare or see an Apple Genius or a technician.
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What happens when I pull the plug?
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