|Have you tried holding down the Power button on your laptop for about 10 seconds until it turns off completely? (the green light should go off). Then try turning it back on again.|
Assuming the above doesn't work, could you connect the laptop to an external monitor via the VGA port and turn it on? If it works with the external monitor, then your laptop screen / laptop screen connector would need replacing. If the laptop doesn't work with the external monitor then you probably have a dead graphics unit, in which case you would need a new motherboard (but more economical to buy a new laptop).