I've had my ASUS for only a few months and it works like a charm, but I noticed a few days ago that it's not going into sleep mode anymore. The only changes I've made were:
1. Installed nod32 (antivirus)
2. Changed my desktop wallpaper
3. Installed the Adobe update
That's it. I didn't change anything else, but now my screen will stay lit up all night if I don't turn it off.
I tried turning the screensaver on, and it works in Preview, but never turns on on its own. I tried changing my wallpaper back. I changed the timing on the power settings. I've turned it off several times. I tried unplugging it and letting it run on battery. I'm using the Balanced power management option. I tried changing the power management option. Nothing works for me.
I've read that other people have similar problems. Sometimes it's a program running in the background that Windows sees as user activity... one guy said he uninstalled Norton and reinstalled and that fixed his problem. Sometimes it's an optical mouse, some random device plugged into a USB slot, or weird settings. There are a lot of people complaining about it, and now I join their ranks. I have no idea what to do.