Really Simple Solution Below!
[Update 9/6/2009: I have today confirmed that the cause of hibernation bug is Disk Cleanup, most likely the option [x] Hibernation File Cleaner checked at the time of Disk Cleanup. Did that and found myself with the original symptom. Repeated the solution, was in good shape. The problem/solution reconfirmed.]
SYMPTOM OF ANNOYANCE
Laptop won't come out of hibernate/suspend/sleep after pressing the wake-up button. Shows a few blinking lights and a blank screen. It would wake up if I wait less than 1 minute after putting it to sleep. It will not wake up if I wait longer. This annoyance happened just about anytime I put my laptop to sleep. Laptop is Acer Aspire 5570z. However, I found that the problem appears on other brands as well.
POSSIBLE BUT UNSUCCESSFUL SOLUTIONS
So it looked more like the Microsoft Vista support issue. I didn't think of contacting microsoft vista support as my laptop was 1 year out of warranty. Googled all over the web for:
acer 5570 sleep blank screen
acer aspire sleep resume
laptop vista sleep resume blank screen
acer screen blank resume sleep
acer aspire wake blank screen 1 minute
I found suggestions that that could be because of the display driver being outdated. People suggested reinstalling display driver. I tried that. Turns out the display driver at Acer website is actually older than the one I got through Vista Update. Go figure. Replacing the display driver didn't help with the blank screen problem.
Some people suggested putting the laptop to sleep by closing the lid. Tried that. Laptop would still not wake up.
Some people saw the annoyance with the AMD processor. Well mine is Intel. Never mind.
Some suggested setting minimum CPU processor speed back to 100% and disabling screensaver. I did that, didn't work.
Some suggested removing ACPI Lid from the System Devices under Device Management. That "solution" is now preventing my laptop to go to sleep when I close the lid, nothing more.
Note: I resolved The ACPI Lid annoyance later here. Easy but interesting.
Some people had problems with not being able to turn the computer on at all (now that really hurt). Solution to that was to take out the battery and press the ON button for like 60 seconds. Weird!
My annoyance was weird too. Especially because the problem appeared intermittently, not every single time. But it happened frequently and the only thing I could do was to push the power button and reboot. With Vista, that takes forever! Vs. just a few seconds when you put it to sleep or hibernate. Plus, I lost some of my valuable data in running programs and lost the system status. Oh, yes the problem also happened with hibernate. Same thing, intermittent.
So what is the solution? I finally found it with a guy named Larry at howtogeek.com: http://www.howtogeek.com/howto/windows-vista/disable-hybrid-sleep-mode/
My memory of recent activities on vista supports the possibility that by a recent disk clean up I erased or disabled the hibernate file. Great job Microsoft! The solution is to restore the hibernate file, see quote below. The procedure takes about a minute. Restoring the hibernate file worked for me! It is incredible this solution still needs to be invoked in 2009, two years after the problem was found!
Quoting the solution:
From Larry @ howtogeek:
Did this solution help you? I want to hear from you! Go ahead and post a comment below and let me know if the solution worked for you!
Maybe the solution did not help you? It's possible, of course. If you feel that hibernate is not your problem, but suspend and sleep is, here is anoter possible solution: Vista Sleep problem solution #2.
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