SOLVED: Aspire 5100 (or any Vista & AMD computer) - Sleep/Suspend/Hibernate/SCREENSAVER black screen or wake up or resume problem

After a long and painful battle, countless hours of research, a few posts here and other places, here is the solution to anyone who has problems with the computer resuming (waking up) from the screen saver / resuming from hibernate or resuming from sleep/suspend/standby (screensaver is the real explanation) on the Aspire 5100 and any computer with the combination of Vista and AMD Turion dual core processors and possibly also the ATI Radeon built in card.

Symptoms:
Overnight or after a period of not using, the computer doesn't resume when you try to use it. Various lights on the computer, the mouse, and the computer's fan indicate that the computer is on and running, but the computer will never properly wake up. Your only option is to hold down the power key and power off. I've seen dozens, possibly hundreds of posts all over the internet related to this, although most posts focus on Sleep/Suspend or Hibernate as the culprit.

The culprit is actually a combination of the Screen Saver, a CPU intensive background task (that might kick off overnight), Windows Vista, and power-saving settings for the AMD CPU. When the screen saver kicks in, it seems that the CPU goes into low-power mode, and IF a CPU intensive task (virus scan, etc.) kicks off, problems will happen. In an ideal world, Microsoft and AMD will figure this out, but for now, you have to use one of the workarounds.

Workaround Solution 1 (better):
Go to Power Settings, then click on Change Plan Settings, then click on Change Advanced Power Settings, Scroll down to Processor Power Management, and set Minimum Processor State to 100 percent for both plugged in and battery. You won't freeze again when you go to the screen-saver, or at some point overnight when a virus scan/spyware scan makes the CPU try to work hard. (You might never have experienced this problem if you've been using the high performance Power Plan).

Workaround Solution 2 (works most of the time, but I like solution 1 better):
Skip screensaver entirely, and rely on "turn off monitor" power setting INSTEAD of screen saver, which basically accomplishes the same thing as a screen-saver. The freeze/wake up problem is actually related to the screen saver running along with a high-intensity task, while the CPU has gone into low power mode.

False Positive: Windows Defender
For a while, I was seeing a connection with Windows Defender "Full Scans" and my problem. In the end, the explanation was that since Windows Defender uses quite a bit of CPU power during a scan, plus the CPU going into low-power mode when the screen saver activated, the two together were making the problem occur. With the resolution above, the Minimum Processor State setting for the CPU set to 100 percent, the problem is completely solved, and Windows Defender works fine, and was not to blame.

Why doesn't everybody have this problem?
Lots of people have the problem, but not everybody. People who choose "High Performance" for their Power Plan will never see it, because that power profile has the CPU Processor States set to 100 percent. People using the "Power Saver" or "Balanced" settings are the ones who might suffer this problem.

Also, the problem doesn't necessarily crop up every time the computer goes to screensaver. It crops up when the computer is under load (as in, like running a virus scan or Windows Defender) while the screen saver is active and the CPU is running half power.

Anyway, I hope this helps. I now can view this computer as dependable enough to count on.

 

Oh, a quick follow-up. There was also a different issue with shut-downs on this same machine. The shut-down problem was improved on, by updating the BIOS, in my case to 3.13 which I got from the Acer Euro site. I had fixed that a few months ago, but discovered that the black-screen problem (not shut-down) continued.

 

Hi John,

Unfortunately, this solution did not work for me! What worked was to re-establish the hybernate file that was erased during disk cleanup!

Here is the detailed description of the solution:

http://annoyances-resolved.blogspot.com/2009/08/laptop-wont-resume-from-sleep.html