Most laptops use a very thin long fluorescent type tube to illuminate the screen. To operate the tube requires between 300v - 700v. The high voltage is required as it increases the efficiency giving more light for less battery power. The problem is that such a high voltage requires special electronics to generate it; this is called the inverter. It is very common for the inverter to fail especially if the laptop is subject to damp conditions. This is the commonest cause of a dark image on the laptop screen. If the laptop has been dropped or is very old or has been used for a very long time then the tube itself may have failed. If the hinge has been damaged or the lid is open/closed very frequently then the cable linking the laptop motherboard to the laptop screen may have broken resulting in a dark screen that may be intermittent as the screen is moved. Occasionally, a fault may develop on the laptop motherboard preventing the voltage getting to the inverter resulting in a dark screen. Very occasionally, a fault may develop in the lid switch resulting in a dark screen.

The above faults can all be repaired by a competent laptop repair company.

The latest designs of laptop use different hardware to generate the screen display; they use a led array. This has the great advantage that a high voltage source is not required, there is no tube to break, and they use less precious battery power. They still occasionally fail most commonly due to a broken screen cable where it passes through the hinge. Rarely, a motherboard fault can also result in failure.

If you have some urgent work or important data and you cannot immediately get the laptop repaired then you can connect a standard monitor to the VGA port on the laptop. Provided you turn on the laptop with this connected then you should get a picture. Sometimes it is necessary to switch displays from the laptop screen to the monitor screen by pressing the FN + other key. This is different for each laptop. If you are unlucky the laptop will not have a VGA port in which case the only action is to have the laptop repaired.

Always treat your laptop with great care as the screen and backlight can very easily be damaged!