Try this...
1. Turn off the laptop (off not hibernate or sleep).
2. Connect an external monitor to the laptop.
3. Turn on the external monitor.
4. Turn on the laptop.
Can you see everything fine on the external monitor?
If yes you can, then the attached display or the ribbon cable that connects it are your problem.
If no, you can't see on the external monitor either, then the graphics card/GPU is probably the issue and will need replacing (you may need to replace the motherboard as well).
NOTE: Before opening up the device to do any work yourself, or have anyone else do the work, make sure that the device is no longer under warranty. If it is under warranty, you don't want to void that so contact the manufacturer first.