Okay, here is what i have discovered. WHen the battery is plugged in and i'm on AC adapter, the electrical sound is there. When the battery is not plugged in, the laptop seems to be very quiet. By the way, the other discovery that i was talking about in the previous post, u can disregard it because i realized i was running RMCLOCK utility while having battery plugged. RMCLOCK Utility seems to be running at 99% of CPU LOAD all the time, therefore u won't hear the electrical sound cuz the comp is not on idle. Well, the laptop is going in for repair again today, i hope they could find out the issue. I might be a faulty battery. But it is worth mentioning that the sound comes on when battery is plugged.