What Causes Computer Monitors to Go Black?

By Jane Williams

Computer monitors go black for a number of reasons.
i Ryan McVay/Photodisc/Getty Images

A black computer monitor conjures simultaneous feelings of confusion and panic within most computer users, especially if the computer issues the normal sounds of a working machine. Nonworking monitors on seemingly working systems generally stop displaying images for a number of reasons, most of which are fairly easy to troubleshoot. Move in a logical manner to eliminate the simplest reasons for the black screen, starting with the monitor's various connections to the power source and computer itself.

Loose Connections

Many easily fixed factors can cause a dark monitor, such as loose connections in various cords and circuit boards. Check the monitor's adapter plug to make sure it is securely fastened to the back of the monitor and plugged into the outlet or surge protector, allowing the device to receive the proper flow of electricity. Verify that the video cable connections are tight and secure, in both the monitor and the back of your computer. Ensure the graphics card is seated snugly in the motherboard, with all the necessary wires and cables connected properly and securely.

Faulty Video Card

The video card inside your computer's tower allows the translation of electronic data into visual images. If this card fails, through damage or manufacturer defect, your screen will go black. Try a different monitor on your computer and watch for a display. If the second monitor shows nothing, your video card may be at fault and will need to be replaced. If the new monitor does show a normal display, you know your first monitor has failed.

Motherboard Failure

In some instances, your video card is fine, but the large circuit board it's attached to isn't. All the components within your computer's case connect to the motherboard, a large circuit board that allows the various pieces of hardware to communicate and interact properly. If the motherboard suffers a short circuit, from a spill or electrical surge, it may malfunction and be unable to read and use the various cards and components attached. Examine your motherboard for signs of damage, such as burn marks from a short circuit or warped areas. Try a different video card in the motherboard and see if your monitor's image returns. If not, you may have suffered motherboard failure, which requires replacement of the entire board.

Faulty Monitor

Sometimes a dark monitor occurs simply because the device itself has reached the end of its life span. Electronics inside the monitor can fail, or environmental factors such as high levels of humidity may introduce moisture inside the unit, causing a short circuit. Connect your monitor to a different computer to see if it will work. If not, the monitor itself is faulty and requires replacement. If the monitor does display an image, then you can continue troubleshooting to narrow down the true culprit and correct the problem.