On the left side edge of the laptop there is a small LED. According to the specifications, this is what it means: Solid white—Power adapter is connected and the battery is charging. Solid amber—Battery charge is low or critical. Off—Battery is fully charged. Unfortunately, that laptop does not have an LED to indicate when the laptop is in sleep state.
Greetings of the day, I have recently purchased Dell Inspiron Core i5 5510. I do not see Power LED on the laptop. I can't figure out if my laptop is turned on or off. There seems to be something on top of Power button located on top left corner next to the charger socket. But its never ON nor flashing in the state of computer running or sleeping. How do I know if my laptop is in on state or its sleeping. Thanks. 
Inspiron 5510 No Power LED