Easy fixes for different computer screens

A malfunctioning computer screen doesn't necessarily mean a trip to the computer store. Many common screen issues are minor in nature and easy to fix.

Get a clear view without scratching

Older glass-fronted CRT (see below) screens are tough and resilient, but most computers today have LCD or LED screens. Cleaning these with paper towels is a no-no — paper towels are abrasive and can cause scratching. Also, avoid alcoholic solvents (such as isopropyl alcohol), which can attack the plastic material used in LCD screens.

• Rub the screen with a dry, lint-free cloth. Use the smallest amount of pressure that works.
• If the dirt proves stubborn, don't rub harder. Instead, soak a cloth in screen cleaning solution and rub again. You can buy this readily from stationery and computer retailers, or you can mix an effective substitute from equal parts of white vinegar and distilled water.

Check that you're connected

Look for signs of life in your monitor — can you see a glowing power light, a faint glow from the monitor or a "no signal" message on screen?

• If the monitor is on, the chances are that your computer is switched off or has gone into power-saving mode. Press its standby button, move the mouse or tap a key to "wake it up."
• If the screen shows no signs of life, push its power plug in fully and check its connection to the computer. Ensure VGA or DVI plugs are tight in their sockets; most have screws that can be hand tightened to ensure a good connection, so check that they are firmly in place.
• Check that the pins of the VGA plug are straight — one can easily get bent out of shape when the screen is plugged and unplugged from the computer. If a pin is bent, use a pair of long-nose pliers to restore its shape.
• Still no luck? Try connecting the monitor to another computer. If it works, the problem may lie with your computer's graphics card, which may have come loose or may need to be replaced.

CRT: A cathode ray tube, is a vacuum-sealed glass tube. At its flattened end is an array of phosphor dots that makes up the screen. These screens are typically bulky and heavy, like old-fashioned TV sets.

LCD: A liquid crystal display is typically flat, thin, light and delicate. It works by using tiny segments filled with liquid crystal that block or transmit light from a source behind it.

LED: A light-emitting diode screen is light, bright and flat; it is the newest of the computer monitor technologies.

VGA: Video Graphics Array is a type of video connector designed in the 1980s that uses an analog rather than digital signal. Its plug has 15 pins arranged in five rows of three.

DVI: Digital Video Interface is a more recent connector designed to carry digital signals. Its plug is a large rectangular connector with as many as 28 pins.