So you are able to see your icons on the laptop display even when the screen went almost totally black, right? Can you hear the fan spinning or the hard drive spinning while the screen is black?
The problem that you have might be due to the failure of the video chip. You can open your laptop and check if the paste on the video processor has got unsoldered and replace it or you can bring your laptop to a technician to get it soldered again. Also, you might want to check of the LCD inverter cable if it's ok.