Identifying the Correct Video Connectors to use on your Computer to Prevent No Video

Table of Contents:

1. Introduction
2. Digital compared to Analog
3. Common types of Display equipment
4. How to connect up your monitor and avoid a No Video error
5. Connecting up multiple cables for several displays

Introduction

This guide discusses the benefits of a digital signal as opposed to an analog signal and media.

It shows the various common display types in use by most of our users.

It takes you through the correct set-up for a single display and how to avoid a No Video issue during setup.

It also takes you through the correct set-up for multiple displays as well.

This is a general guide. The steps advised should enable you to work confidently on any computer by knowing why you must complete each step.

Digital compared to Analog

Analog Signals:

These are any continuous signal for which the time-varying feature (variable) of the signal is a representation of some other time-varying quantity. (For example: Analogous to another time-varying signal.) It differs from a digital signal in terms of small fluctuations in the signal which are meaningful.

Digital Signals:

These use discrete (discontinuous) values. By contrast, non-digital (or analog) computers use a continuous range of values to represent information. Although digital representations are discrete, the information represented can be either discrete, such as numbers or letters, or continuous, such as sounds, images, and other measurements of continuous systems.

What does that mean for you?

The most common analog cable still in use is VGA. Support for this standard was supposed to be dropped with Windows 7. However, it is still widely in use and support has continued through Windows 10. However, although it is still in wide use that does not mean it is a good interface to use.

The benefits of using a digital cable depend on the type of cable and interface/standard in use. These vary through DVI, HDMI, DisplayPort and Thunderbolt cables, connectors and standards. Generally, however, there are certain benefits across all digital cables and graphics cards. Such as:

• A more consistent signal
• Larger screen resolution and faster refresh rates
• Longer cable lengths
• Better cable shielding means less signal interference
• The addition of audio and Internet signals to the video signal
• Multiple displays
• Future-proofing your computer setup

This is why we always recommend using the best standard possible, that works on both your computer and your display.

If you would like further information about the different cable types and their properties, check out the following articles in our knowledge base:

• What Are the Differences Between the White Digital DVI and Blue Analog VGA Ports on My Dell Graphics Adapter?
• Frequently Asked Questions (FAQs) about the DisplayPort port on a Dell Computer
• Frequently Asked Questions (FAQs) about the HDMI port on a Dell Computer
• Frequently Asked Questions (FAQs) about the Thunderbolt port on a Dell Computer

If you would like to see a visual guide to identifying the various cable connectors and plugs, check out the following article:

• A Guide to the External Ports and Connectors on a Dell Computer

Common types of Display equipment

There are many different types of display available. The more recently it was made, the more advanced its quality and function tends to be. The table below shows some examples - starting with the oldest and working down to more recent models:

CRT Monitor:
Projector:
Flat Panel Monitor:
Widescreen Flat Panel Monitor:
Widescreen Curved Panel Monitor:
High Definition Television:

How to connect up your monitor and avoid a No Video error

If you do not ask and answer the correct questions when setting up a display on a computer, you may experience a No Video issue. I take you through the correct questions to ask below. I show you some of the most common ways to set up a new computer and display.

1. Check the back of the display and identify which port types and video cable types are available for you to use? (There is more than one port on the display (See figure.1) and appropriate cables (See figure.2) are supplied with the display.)

   • You can use the guides linked in section 2 to identify which is the best port and cable type available to you.

   • You match this port to one on the computer or device that you want to connect the display to.

   • (It is possible to purchase conversion cables (See figure.3) that allow you to plug a cable with different connectors that have compatible video standards. We do not go into this further, other than to say it is possible. However, these cables are not supplied with the equipment as standard.)

   

2. Does your computer have an add-on graphics card fitted or is the onboard video the only port available? (Graphics cards can come in multiples and fill more than one option slot (See figure.4) on your computer.) Check the back of your Desktop, Laptop, or the back of your Dock (If using a closed Laptop) and identify which video ports are available. (Check if there are any video ports which are blocked off with a plastic cap?)

   • Generally for Desktop computers, when the computer is standing up like a tower, the onboard video ports run in a vertical strip (See figure.5). The video ports on a fitted graphics card run horizontally (See figure.6).

   • It is possible to add extra graphics to Laptops (See figure.7) and Docks (See figure.8), generally, you would pick the best video port available on either to work with on the dock.

   

3. If there is a video card fitted, select the best port available from the card that matches the port and cable from the display and plug up the correct video cable between the two ports. (Ensure that there is power to both the computer and the display) If there is no card fitted, select the best port available from the onboard ports and match that to the port and cable from the display.

4. If there is a video card fitted (See figure.9), most computers disable the onboard video ports in the systems BIOS. You can enter the BIOS on a Dell computer by rapidly tapping the F2 key before the computer POSTS. You can disable this option manually. However, you would only do this if the onboard port is the only one you can match to a port on the display. (You may do this if you are setting up multiple displays and need several video ports to connect to.)

   

5. Once you have connected everything and turned on your computer, you must configure your video output. The video section of the Windows operating system handles it for onboard video. With add-on graphics cards, there is usually a proprietary configuration program for you to use instead. With only one screen installed, this would mostly be a case of setting the correct resolution and refresh rate for your screen type.

Connecting up multiple cables for several displays

Connecting and setting up multiple displays on your computer starts the same as in section 4. There are some additional steps depending on how many displays you are looking to attach.

• How many video ports are available 
• How many video channels are available from the onboard video chip
• How many video channels are available from the add-on video chip
• What equipment do you have available to you?

1. Check the back of the display and identify which port types and video cable types are available for you to use? (There is more than one port on each display (See figure.1) and appropriate cables (See figure.2) are supplied with the displays.)

   • You can use the guides linked in section 2 to identify which are the best ports and cable types available to you.

   • Match these ports to those on the computer that you want to connect the displays to.

   • (It is possible to purchase conversion cables (See figure.3) that allow you to plug a cable with different connectors that have compatible video standards. We do not go into this further, other than to say it is possible. However, these cables are not supplied with the equipment as standard.)

2. Does your computer have an add-on graphics card fitted or is the onboard video port the only one that is available? (Graphics cards can come in multiples and fill more than one option slot (See figure.4) on your computer.) Check the back of your Desktop, the back of your Dock or the back and sides of your Laptop and identify which video ports are available. (Check if there are any video ports which are blocked off with a plastic cap?)

   • Generally for Desktop computers, when the computer is standing up like a tower, the onboard video ports run in a vertical strip (See figure.5), where the video ports of a fitted graphics card run horizontally. (See figure.6)

   • It is possible to add extra graphics to Laptops (See figure.7) and Docks (See figure.8), generally, you would pick the best video port available on either to work with. However, Laptops usually need a compatible dock to have more than one external screen directly plugged to it, but remember with the Laptop open and the integral screen on - the LCD plus one external screen count as two displays.

3. If there is a video card (See figure.9) fitted, select the best ports available from the card that matches the ports and cables from the displays and plug up the correct video cable between the various ports. This is where you would disable the BIOS option turn off the onboard video ports to allow you to use them in addition to those on the video card. (Ensure that there is power to both the computer and the displays.) If there is no card fitted, you may not be able to fit more than one external display unless the computer has multiple onboard video ports and the channels to use them separately.

4. Once you have connected everything together and turned on your computer, you must configure your video outputs. The video section of the Windows operating system handles it for onboard video. With add-on graphics cards, there is usually a proprietary configuration program for you to use instead. Where multiple screens are plugged up, this is a case of:

   • Setting the correct resolution and refresh rate for each screen type.

   • Setting whether screens are in Extend or Clone mode:

     Extend:

     This is a mode where the desktop is extended across multiple screens.

     Clone:

     This is a mode where the desktop is identical across multiple screens all showing the same thing.

   • Setting the displays in the correct order and location. (So your cursor can navigate across each screen when in Extend Mode.)

   • Choosing between Portrait and Landscape view depending on each screen position:

     Portrait:

     This is the mode where the long sides of the rectangle are vertical.

     Landscape:

     This is the mode where the long sides of the rectangle are horizontal.