If your Dell Inspiron laptop computer won't turn on no matter how many times you press the "Power" button, its motherboard is likely holding an excess electrical charge. This will keep the laptop from turning on even if it is plugged into a wall outlet or if the battery is fully charged. To fix this issue, you will need to dispel the extra electrical charge from the Inspiron. This also involves the "Power" button.
Remove the battery from its compartment on the side of your Dell Inspiron laptop computer.
Remove the power adaptor from its plug on the side of the Dell Inspiron (if your laptop is currently plugged into a wall outlet).
Press down and hold the "Power" button on the laptop for one to two minutes. This will dispel the excess electrical current that is built up inside the laptop.
Put the battery back inside the compartment of your Dell Inspiron.
Plug your power adaptor back into the side of the Dell Inspiron. Press "Power." Your laptop computer will now turn on.