Video Cables – CompTIA A+ 220-1001 – 3.1

January 6, 2019


There are many different ways to connect a monitor to our computers. In this video, you’ll learn about VGA, HDMI, DisplayPort, and DVI video cables.

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What type of video cable is being used between your desktop computer and your monitor? In this video, we’ll look at the many types of video cable connections.

A type of video connector that’s been around a very long time is VGA. This is Video Graphics Array, and you’ll often see this described as a DB-15 connection. The 15 means there are 15 pins inside of this connector, and the DB is referring to the outside connector type on this cable. This is actually a DE-15 connection. The smaller D-type sub miniature connection is the E size, and you may see this described as either DB-15 or DE-15 if you’re looking for a VGA cable.

Another thing that’s very standardized on these VGA connectors is the color blue. Not only will you see the color blue on the connector, you’ll often see motherboards with the connectors themselves having this blue color. That’s because there’s a standard called the PC System Design Guide which assigns different colors to different types of connectors, and for VGA, we have this blue color.

A VGA connection is an analog connection. There’s no digital option if you’re connecting with a VGA connection. This means if you extend a VGA cable over a distance of even five to 10 meters, you’ll start to see that the image itself would become fuzzier and fuzzier as that distance increases.

One good test for anybody who’s taking their A+ exam is to look at the back of a motherboard and be able to recognize all of the different interfaces and connectors that are on the back. For a VGA connector, we only need to look for the connector that has 15 pins, and these 15 pins in these three rows with this DE connection is our VGA connector on this motherboard.

One of the most common video connection types today is an HDMI connection. That stands for High-Definition Multimedia Interface. This ends both audio and video through this HDMI connection, and it is an all-digital connection. There is no option here for sending an analog signal through an HDMI connection.

Usually you can extend HDMI connections up to about 20 meters. And since this is a digital connection, after that 20 meters, you may start to see dropout or have no signal at all because you’re not able to get enough signal from one end to the other. An HDMI connector is usually this A connector. This is a 19-pin connector, and it’s proprietary to this HDMI type. There is a smaller HDMI connector called a miniHDMI. It’s a Type C connector, and it’s designed for smaller devices such as video cameras.

Here’s a video card, and this is the back of the card that would extend out the back of a computer. And you can see, there is an HDMI connector right there at the bottom. This card also supports other types of video connectors as well. For example, there is a DisplayPort connector and two different DVI connectors. We’ll talk more about DisplayPort and DVI in just a moment.

DisplayPort is a standard created by the Video Electronic Standards Association or VESA. It’s a royalty-free standard, which means manufacturers can add DisplayPort interfaces to their components and not have to pay any royalties to VESA. The data is sent over this DisplayPort connection in a packetized form, very similar to sending information over an ethernet network.

It’s also compatible with HDMI and DVI, which means you could use a passive, unpowered connector to be able to convert between DisplayPort and HDMI.

There’s two different kinds of connectors you might see for DisplayPort. One is this smaller Mini DisplayPort connector, and some of the larger components like the video card we just saw is using the standard sized DisplayPort connection. Notice that the connector of the standard DisplayPort is a U-type connector, and it has a corner that is at an angle. So if you were to look at the components on a laptop, for example, you can easily pick out that DisplayPort which has that U connector on the inside and that corner that’s a little bit different than the others.

Another common video type that you might see as DVI. This is Digital Visual Interface connection, and there are a number of different types of DVI connections. There are single and dual link DVI connections. The single link supports 3.7 gigabits of throughput which allows you to have HDTV at 60 frames per second. For gaming and other applications that need even higher resolutions and higher frames per second, you can connect a dual link connection with DVI which extends this to 7.4 gigabits per second supporting an HDTV connection at 85 frames per second.

DVI supports both analog and digital communication. The DVI-A connector supports analog signals, DVI-D means that you’ll be sending digital signals through a DVI connection, and DVI-I is an integrated connector that will send both digital and analog signals through the same connector.

Here’s the end of a DVI cable. We know that this DVI cable supports the digital version of DVI because of the grouping of the pins on the cable itself. If we go back and look at that video adapter card which had the DisplayPort and HDMI connector on it, we saw that there were two separate DVI interfaces, and you can see they look a little bit different with the pin configurations. The top connector is a DVI-D that can support digital video, and the bottom connector, which looks a little bit different, is DVI-I that can support either digital or analog video.

Here’s a relative view of these cable connections next to each other– the VGA, the DVI, and the HDMI. And depending on your video requirements, you may be using one of these to be able to connect video to your desktop computer.

Category: CompTIA A+ 220-1001

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