Computer won't go to sleep plugged in

My laptop won't go to sleep when It's plugged in for some reason, though if I take out the power cable it will sleep. If I have the power cable out, send it to sleep then plug the power cable in this doesn't wake it up.

I've gone into the power option's but I'm not too sure what I can really change to make it work.

I've changed the multimedia setting's to allow the computer to sleep
I've tried the different power plans - same behaviour

Not too sure if there's some application that's only on with connected power or what..


Settings are:

The Powercfg.exe utility might be useful is such a situation. You can open an Administrative command prompt and type powercfg /? and see a list of the options available. The /energy or /requests might supply some helpful information.

If you use the /energy, it will create a report in the .html format and store it in a folder. Make note of the location and copy the file to the desktop to open. There always seems to be USB warnings at the front, so you might bypass those for the time being.

I don't have a laptop, but in the power option for Sleep section, does it have plugged and unplugged options for the type of sleep allowed?

Any chance there is some Bios setting for power management? It is strange what you might find in the bios. On my new system, I found an entry for allowing the Network Adapter to wake the computer.....

ok, I have an..asus notebook X502CA windows 8.1 and it WOULD NOT go to sleep when plugged in...i fixed this by going to control panel>system and security>power options>change plan settings (for the plan that is active)>change advanced power options>Multimedia settings>when sharing media, make sure that when plugged in, it is on prevent computer from idling to sleep

Mate, an especially popular alien sent me a bunch of tutorials for problems like these. See if they help at all:

1. Power Options and Sleep Mode Problems
2. Wake Source - Read Event Viewer Log - Windows 7 Help Forums
3. Lastwake Command - Windows 7 Help Forums
4. Devices - See Devices that are able to Wake Up the Computer - Windows 7 Help Forums
5. Devices - Allow or Prevent to Wake Up Computer - Windows 7 Help Forums
6. Windows Media Center Updates - Enable or Disable Waking Computer - Windows 7 Help Forums