The screen of a user's laptop computer is blank, despite the fact that the power and other indication lights are turned on. When you connect an external monitor and flip the LCD cutoff switch, an image shows on the external display. Which components are MOST LIKELY to be at fault?

If a laptop fails to display video, the problem could be with the screen or the video card/integrated video. To test it, connect an external display (that you know works) and switch to external video output using the function keys on the laptop. If that doesn't work, the video card is most likely faulty. If the external monitor works, you know the problem is with the laptop's display. It is possible that the backlight (or inverter) has failed, or that the screen has failed.