Solved Computer won't go into sleep mode

[coffent]

Up until a few days ago I was able to put my Windows 7 computer into "sleep" mode, either manually or via inactivity. Now, however, when I try, the monitors shut off but the computer itself keeps running. Hitting a key or moving the mouse makes it immediately turn on. I've made no changes to the system that I'm aware of. As before, I have "Sleep after" set to a certain number of minutes, and "Allow wake timers" set to Disable. Is there any other setting that could possibly have been changed?

 

[file3456]

I hate to say this, but sleep mode and hibernation mode really shouldn't be used as they can cause issues. I've seen it many times and on many computer forums. You should just shut down the PC completely.

What happened could be the power management settings went arye. You could try the power options in the control panel and reapply your settings then reboot and see if that fixes it. Other than that I recommend you just shut down the computer. Updates can also give you issues.

 

[coffent]

Yes, I realize that sleep mode is dicey. I always put the computer into that mode with the recognition that it may not recover without a reboot. Nevertheless, it's useful.


Reapplying settings didn't help. I've since checked that the computer (alone) draws 120 W when running, 104 W when in "sleep" mode. So the computer is apparently making some change when I try to engage sleep mode, but it's not shutting down completely.

 

[mrjimphelps]

In sleep mode, your computer should draw minimal power, just enough to keep the circuits active and the information preserved in memory. Although I don't know how much that will be, 104 doesn't sound "minimal" when compared to 120; it sounds like it is drawing a lot of power while sleeping.

Here is a person who tested and found that his system pulled 3-5 watts while in sleep mode.

 

[coffent]

Yes, I agree. That's why I'm saying that sleep mode isn't working correctly (but the fact that power consumption decreases by ~15 W means that *something* is happening).

 

[mrjimphelps]

I suggest that you go through your power settings thoroughly, and eliminate sleep and hibernate everywhere. Set everything to where the computer is always on and always at full power.

Now go through the settings again, turning on sleep only where you want it to be. See if that fixes things.

If that doesn't fix things, then perhaps you have some malware on the computer. Or maybe there is a hardware problem.

 

[file3456]

Have you added a recent hardware or software prior to this happening?

 

[coffent]

I found the problem. Apparently after a crash the BIOS suspend mode got set to the default S1 rather than S3. Changing it back to S3 fixed the problem. (I should have checked my troubleshooting log earlier - I found that I'd had the same problem about 7 years ago, but had forgotten about it in the meantime.) Thanks everyone for your suggestions!