07-21-2012 08:30 AM
It could be a short in your power adaptor cable, break or crack in the power jack that the power adaptor plugs into, a failing power inverter (small long thin circuit board in the screen that converts DC back to AC) or some unusual setting in the power setting for the laptop. I have no idea what that last one actual is but I am guessing. Look at the notebook and note which lights are on when it is bright. See if the external power light goes out when it goes dim. This happens when you go from plugged power to battery. Try to run the notebook with the battery out of the system for a day and see if you still have the problem. Maybe the battery is starting to short out.
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