How do I connect a monitor to my laptop and have it work?

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Summary: Most laptops include a VGA or DVI connection for an external monitor. Setting it up is relatively easy, if you know the tricks and have patience.

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I see people struggle with this all the time. It's actually somewhat frustrating, since the answers are actually simple, just not obvious.

You need to know the magic keystroke.

And you need patience. Just a few seconds worth, but you absolutely need it.

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Most laptops built today include an external monitor connection. Most are VGA, but some are starting to include DVI digital video connections instead.

The back of my Dell laptop, highlighting the VGA connector.

The 'trick', if you want to call it that, is that they are not enabled by default. You need to take action to send video out that port. Typically, and this varies from laptop to laptop, there is a keystroke that does exactly that.

The CRT/LCD selection key on my Dell Laptop

Unfortunately, it's not a simple as turning it on or off.

First, realize that in order to enable the CRT/LCD keystroke you typically need to be holding down an additional key; on my Dell it's a blue "Fn" key. It operates very much like CTRL or SHIFT, in that you hold it down to enable the blue functions that are printed on the key tops. So in my case it's Fn + CRT/LCD to enable the external monitor.

Second, realize that it's not on/off. Pressing the key repeatedly cycles though a series of combinations. For example, each time you press that key, you may cycle through these combinations:

• LCD (laptop screen) only, the CRT (external screen) is off.

• CRT only, the LCD is off.

• LCD and CRT both on, and displaying the same thing on both screens.

• LCD and CRT both on, but displaying different things - together they form a larger virtual desktop where the LCD might be displaying the right side, and the CRT the left.

When you type the keystroke, the configuration changes to the next one in the list; when you reach the last, it starts over at the beginning.

Your list of configurations or combinations may be different, or in a different order. There is no standard, and each laptop may be different.

Third, and this is perhaps most important because it's the source of much frustration, it can take up to 5 or even 10 seconds for each new setting to take. And 5-10 seconds is a long time when you're standing in front of people trying to ready your presentation. I continually see people get very frustrated when they try, wait one second and assume that because it didn't work instantly it didn't work at all, and keep trying thinking that nothing's working.

If you take nothing else from this article take this: after typing the keystroke to change your LCD/CRT configuration, give the new combination at least 5 seconds to take before you decide it didn't work. Be patient. There are several hardware related reasons for this; most typically the time it takes your CRT or projector to 'sync up' to the signal that it's suddenly receiving.

The last combination where both your laptop screen and your CRT are on and displaying two different portions of a single virtual desktop warrants a little more clarification.

The likelihood of the LCD and the CRT being the same resolution or "size" in pixels is very low. You can see this when you look at the display settings in Windows:

You can see that while my laptop's LCD is 1440x900, the CRT/VGA output is set to 800x600. While you can often change the resolution of the VGA output, it's unlikely that you'll be able to match the native resolution of your LCD. The result is what you see - a virtual desktop that's not a perfect rectangle. That's something you simply need to be aware of as you move applications between the two for your display.

I'll admit that it can be a little frustrating at first to get the hang of how your laptop handles external monitors and how those external monitors react, but once you do you'll find that the external VGA output on your laptop might be one of its most important features. Just ask anyone who's made presentations in front of an audience.

Article C3570 - November 22, 2008

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