I cannot promise an easy fix for this and you will need to work through the following to eliminate possible causes.
1.) Try the laptop on another monitor, if it works on this, you can eliminate the graphics chip, which is the part that usually causes problems with blank screens. If the external monitor does not work with the laptop, you will need to investigate the problem by stripping the laptop.
2.) If it does work on an external screen, the inverter, the backlight or the VGA cable are at fault. If you can see a very faint image on screen in a darkened room, the possibility is that the backlight has failed, if there is no image, the inverter has failed. Of the two, the inverter is the cheapest to replace at about £10.00, whilst the screen will cost about £40-70 to replace. (The vga cable may have also come loose, unlikely, but stripping the laptop by removing the screen assembly will show this. You would also need to do this to replace the inverter and / or screen.)
3.) Before stripping the laptop, try these steps:
- Check the Adapter is putting out the correct voltage by connecting a multimeter set to 20volts DC to the DJ jack that plugs into the laptop. The red probe should connect to the inner of the jack and the black probe to the outer. If you get a lower reading, suspect the adapter is at fault.
- Check the port that the adapter plugs into, it should not be loose or wobbly, if it is slack, it will require replacing.
- Remove the battery and ac adapter, press the power button on and hold it for 30 seconds, this clears the cmos. Plug the ac adapter back in and try it, if it works ok, reinsert the battery. If it fail again, suspect the battery.
After taking all these steps, and getting no resolution, you should now look into the possibility that the motherboard is damaged, specifically the graphics chip. These tend to fail if the laptop has overheated. They cannot be easily checked, however, stripping the laptop will at least show you if there was dust build up in the CPU fan area and cooling radiator. If this was heavily clogged, it is almost certain that the chip has failed
The link below may help you should you choose to dismantle your laptophttp://laptoprepair.ca/news/11780.html