It's normal that the Dell 19.5V ac adapter's voltage fluctuating between 16 and 19.5V? The fluctuating: the starting voltage is 19.5V, and decreasing 0.2V per second to 16.5V, and the voltage jump 19.5V, then decreasing again to 16.5V. Can I use the laptop with this adapter still? This was the biggest question in my mind. For answer to this question I schedule geek squad appointment . There they suggested to replace the cable that is connected to the power socket. After doing so the problem was solved. Now it is working without any issue.