A major component has gone dead... either the hard drive, or the screen inverter, or the power supply. Since the green light is on, it is fixable. A hard drive is relatively cheap at $40 to $80 and you can do it yourself if you have the recovery disk set from Dell.
The others will all likely require a skilled technician, and costwise, it might be cheaper to buy a new one.
The low priced Dell laptops have a high priced repair cost.
See a technician in your area who will probalby charge you $55 to $85 and hour, and it will take two hours... the parts will not be cheap.