My AC adapter makes a very soft clicking noise (I can only hear it when I put my ear directly up to it) whenever it is charging the laptop and the laptop's power plan is on anything lower than High Performance. The noise seems insignificant and my laptop is running just fine. However a bad AC adapter just killed my previous laptop and I wanted to be more proactive when discovering symptoms that are even slightly similar to my previous situation. What do you guys think is happening? Do you think this warrants a trip to the PC repair shop or is it something that normally happens? I read somewhere that the clicking could be the sound of some sort of safety circuit kicking in due to the high amount of power (170W) that the adapter draws in but I don't want to assume. Also please do not tell me to call Lenovo support because they were a pain with my previous situation and took me shipping my laptop in 3 or 4 times before the issue was "resolved". Any help would be much appreciated and thanks in advance!