With the system running and the laptop's display being used - Take a flashlight or light and point it to the display. Look for faint images on the screen of your desktop or what ever should be displayed at that point. If there are faint images then then the problem is most likely related to the WLED driver & booster circuitry. If there are no images then the problem is something else or you have multiple problems.
Please tell us the results. Do you know how to use a multimeter and do you have one? What kind of optics do you have?