'''Plug is Not Connected to Wall Outlet'''
Check to see if the charger is plugged into the computer and also an outlet. Try a different outlet to ensure that it is not a problem with the power of the first outlet.
'''Dead Battery'''
If your laptop will only function while being connected to an outlet, your battery may be faulty. To fix this, replace your battery.
'''Damaged Battery'''
If your laptop will not turn on, check your battery for any physical damage or water damage. If you find evidence of damage your battery will need to be replaced.
'''Issue with Charger'''
Check to see if the charger is one that is recommended to use by the manufacturer. If not, obtain a recommended charger. Check to see if your device will charge with a different charger. If this is the case you will need to replace the charger you have.