Screen dimming

I have a emachine laptop.. recently the screen has been going dim when I put in the power lead. The lead appears to be working and the laptop is charging... any ideas why this is happening?

It might be changing power profiles to something that has a different brightness setting on the configuration menu, I've seen strange things like that. Maybe start there? I think the eMachines use the "Power4Gear" power utility like other ASUS units. I usually always use the Windows profiles over these ones though.

Does the screen return to the original brightness after you unplugged it? If so, then it's probably like Norbur suggested, something to do w/ the power profile. My Dell laptop's screen dims a bit after it's unplugged and brightens when it's plugged in.

Yeah, you can change this by going into the Control Panel then into the Power options (or in the bottom right you have the battery icon, select it and change power settings) In these power settings you should have a "Brightness" slider bar, push it to the highest. It probably somehow got changed one time.. Another way to do it would be using the Function(Or CTRL)+# keys to change the brightness while it is plugged in.