Try connecting it to an external screen or monitor. If that works its a problem with your video screen . If not remove one dim of ram at a time and try each dim in each different slot if you have different ram available switch out the ram.If that doesn't work it could be a problem with static discharge , if so do the following.
1. Disconect the power cord
2. Remove the battery
3. Hold down the power button for 30 seconds , then release for 30 sec and then hold down for another 30sec
4. Plug in power ,replace battery and power on laptop.
If this causes no Joy then the problem is probably in the video card itself
Hope this helps