Dell Laptop no longer sleeps when lid is closed

I have a Dell laptop running Windows 7 Professional x64 that always went to sleep reliably when I closed the lid. Now it does not. I am able to get the laptop to sleep with the Start --> Sleep option but not with the lid closing and not with the power button.

On the power options interface screen, in the section that says "Power Buttons and Lid" there is no way to set a lid action - there is no choice or link available. It's like someone completely removed the computer's knowledge that it has a lid - maybe it somehow got tricked into thinking it was a desktop?

Now that I'm thinking about it, it may be in some "desktop" mode instead of a laptop mode. Here are other data points:
- It no longer shows the battery indicator in the lower right status bar
- The power options no longer show different options for when the system is "plugged in" vs "on battery power", it's just one setting.
- No more "lid" settings as I said above.

Hmmm - does anyone know how to check this or what a possible fix might be?

Thanks in advance for your help - I appreciate it!

Mike

 

Greetings, mijgilbert.

What's the Dell Service Tag #? I'd like to get the machine specs as reference.

Is the machine running well while being battery powered?

And, are the listed symptoms present in all user accounts?

 

Have you tried this?

http://www.howtogeek.com/howto/windows-vista/re-enable-sleep-mode-in-windows-vista/

 

I just looked at that and it doesn't give me two options (one for plugged in, one for on battery). It only gives one option, which I changed to "allow to sleep" and it didn't fix the problem.

 

Thanks for the help. It's CDXXTL1

Yes machine is running well on battery, but I get no notice that it's low on batteries and then it just shuts off when the battery dies. The blue battery light indicator does not turn yellow and I get no pop-up windows.

I only have one user profile so this is the only one it's happening on.

 

Strange. What tells the machine that the lid is closed? Physical switch, sensor, prox switch? Although that shouldn't affect the power switch.

Maybe look in BIOS, see if Dell put in some weird desktop/laptop or sleep disable setting, but I doubt it.

Just throwing out random thoughts.

 

Yes it is strange. Don't know what tells the machine that the lid's closed - there is no obvious button or switch.

I already looked in BIOS, there is no obvious power setting. (hit F12 on boot)

I am grabbing at straws too... thanks for the help.

 

Can you think of some event that may have happened just prior to the symptoms? Maybe if you've got a System Restore point previous to the problem, you could try that in case this is software-caused.

For that matter, do the symptoms change while in Safe Mode? Or with all of the msconfig Startups disabled?