[ The PC Guide | Systems and Components Reference Guide | Monitors | Monitor Construction and Operation ]

Interface and Cabling

The monitor is connected to the video card through a cable that attaches to a connector on its back. There are a few different connectors used for monitors:

• 15 Pin VGA (Standard): The standard for connecting monitors and video cards today is the 15-pin video cable and connector, also called "VGA" in reference to the standard that first used it. In fact, all modern cards that call themselves VGA or SVGA use the standard 15-pin connector on the video card. Most standard monitors use the same 15-pin connector as well.
• 9 Pin (Older VGA, EGA, CGA): Older displays used a smaller, 9-pin connector on the monitor, meant to match with the 9-pin output of older video cards. Some of these were VGA, but others employed older standards such as CGA or EGA. There are 15-to-9-pin adapters available that will let a monitor with a 9-pin connector be used on a PC with a 15-pin video connector, but most of these monitors are older and not up to dealing with a modern video card in any event.

Warning: Make sure not to use an older digital monitor with a modern (analog) video card, or you risk damaging the monitor. See here for more on the difference.

• BNC Connectors: Some high-performance monitors use special coaxial cable that has a standard 15-pin connector for the video card on one end, but breaks out to separate wires with BNC connectors on them for the monitor. There are usually 5 wires, one for each of red, green, blue, horizontal sync and vertical sync. Some monitors that have BNC connectors on them also have a standard 15-pin VGA, and either can be used. The BNC cable can be expensive, but provides better shielding from noise and interference than the standard VGA cable. It is found much more often on larger, more expensive units.

Some older monitors require a sync signal from the PC in order to know what mode to put themselves into when they are turned on. When using this sort of monitor, you should turn the PC itself on several seconds before powering up the monitor. This will ensure that the monitor sees a video signal when it is turned on so it will work properly.

One distinguishing feature that many people don't pay much attention to is whether the monitor uses an integrated or a separate data cable. Monitors that use separate data cables have a female data port on the back of the monitor, much like the port on the video card, and use a male-to-male cable to attach the two. Monitors using an integrated data cable have the cable coming from the back of the monitor directly with a single male plug for the video card. Both designs work the same, but if the cable is ever damaged, the monitor with the integrated cable will have to go to the repair shop, while the one with the separate cable can be fixed with a $10 replacement.

Next: Monitor Case

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