One easy check is the charger. Chargers normally come with a green light. If it has it and won't light up, then that's your problem. If it doesn't have this indicator, then you will need a multimeter to test for voltages. This is the most common problem with laptops. If after testing your charger, your computer still doesn't work, then you'll need to take your computer apart and check some objects on your motherboard, normally what pops is the voltage regulator called MOSFET.