My name is Shrikanth and I work for the Social Media and Community Team at Dell. When you say the power button is not working, is it physically broken or just non-functional? What is the model of your laptop? If it’s non-functional disconnect all peripherals remove the battery (Only if it has a latch. If it has screws please don’t attempt to remove it) hold on to the power button for 10-15 seconds put back the battery try turning it on. Also check the light status on the AC adapter when connected and not connected to the laptop. Please reply with your findings.