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Can I use my TV as a second monitor?

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Summary: Your TV can often be used as a second monitor, but unless you have a newer digital TV, the results will likely be very disappointing.

I have a Dell Computer with Windows XP and a regular (non-flat) TV. How can I connect my computer to my TV such that I can see everything I am doing in the computer on my TV screen. I am not trying to use the TV as a primary monitor but as a secondary one; like the one you can see in a computer show on TV.

If you're planning on using just a normal, plain old television, let me put it this way:

It can be made to work, but "sucks" doesn't even come close to describing the visual result.

And here's a hint: those aren't plain old TV's you're seeing on computer shows.

The problem is simple: broadcast quality television just isn't the same as a computer's video display.

At best a regular TV display is around 640x480 resolution. Years ago, when personal computers were first introduced to the mass market, they were actually designed to use TVs as monitors, at a default resolution of 320x240, if I recall correctly. (Anyone who had an Apple ][, as I did, will remember the 40 character display width.)

"Those TV's on your favorite computer shows? They're not regular TV's at all ..."

Today, many video cards don't even go down to 640x480 any more. 800x600 is a common starting point, and even then - you've probably got it set higher, since most computer monitors support resolutions of at least 1024x768, if not much, much higher.

Resolutions that simply won't work on a normal TV.

Those "TV's" on your favorite computer shows? They're not regular TV's at all. They're actually computer monitors that support the resolution required to properly display the computer's output.

So. What are your options?

If you can take your computer down to 640x480, you can try connecting it to your TV. Many laptops actually include an "s-video" out for exactly this purpose. Depending on your laptop, it may be treated as a mirror of your laptop display, or as a second monitor, or you may be able to switch between them. You will quickly see that the quality of the display is, likely, very, very poor.

If S-video is not an option, there are converter boxes available from places like Radio Shack that will take a standard VGA connector and turn it into a composite video signal that can be plugged into a TV with a composite input. In general, this results in roughly the same poor quality computer display.

Surprisingly, in both of those cases, video playback can actually look quite good. What I mean is that if you're using your TV as a computer monitor and to do typical things like reading email or surfing the web, you'll be quite disappointed. However if you are playing back a video - say playing a DVD in your computer and watching it on the monitor - it seems to be quite acceptable. My theory is that most DVDs and other videos are targeted at exactly the TV's resolution, and that, plus the fact that for video we're "used to" that resolution, our expectations for that type of display are simply met.

Oh, and as to using it as a second monitor - to mirror what's going on on your primary computer screen: many laptops support using both the internal LCD screen and the VGA (or S-Video) output at the same time, so you may be able to simply hook it up. If you don't have that option, you'll need to get a splitter of some sort that will allow you to take your computer's monitor output and send it to two different devices: your regular computer screen, and a VGA converter box as I described above. Alternately you could purchase a video card that supports TV-out, or supports dual screens.

Now, there is salvation on the horizon, but it'll require a new TV. Newer TV's are going digital, and many do, in fact, have digital (DVI) input - particularly those that are High Definition (HD) ready. In these cases you actually stand a chance of being able to connect your computer directly to the TV. The TV may not support the same higher resolutions that your computer monitor might, but they'll almost certainly support resolutions that are much more acceptable for computer usage.

(All this is based on my own set of experiences some time ago attempting to do exactly what the questioner was asking. If there are particularly new or novel solutions to this problem that I've overlooked, I'd love to hear about them too. Just leave a comment below.)

Related:

Article C2597 - March 19, 2006

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Recent Comments
30 Comments

hi leo ive got a hp compaq laptop i connected it to my tv it work fine then some settings came up somthing about do i want mirror or not i changed it so i could just see it on my tv well i fault i did but i didnt now every time a attach the lead from my tv to my laptop both screens go blank can u please help me

Posted by: lee at May 16, 2009 2:40 AM

I have a Dell laptop and I want to use my LCD as my monitor but each time that I get to connect them together, the TV turns blue, so I closed the laptop and works for 15 or so seconds and then, oviouslly, the laptop turned off and that is my issue, I have one cable connected to both items, the RGB-PC

Thanks

Posted by: Gonzalo at June 8, 2009 7:40 PM

Just managed to connect my laptop to new wide screen tv with s-video, and got colour. My new problem is that I can´t get it to display anything but the selected wallpaper, and as I wanted to use the laptop and tv as a karaoke machine I need the tv to display whats on the laptop screen, just a click of which button, I´ve tried them all. Please advise

Posted by: David Brown at June 13, 2009 9:45 AM

Hi Leo,

I have a spny vaio laptop with a 4-pin s-video output and I would like to play dvds from my laptop and display them on my tv. now my tv is a little bit older because it has teh s-video ouput as well but not the s-video input. I know there is a small peice i need to purchase and it may be called the rca (female) but I might be wrong. I kind of know what im doing but i do not know the names of the cord i need to buy. I know i need three things: s-video cable, s-video input rca female thing, and a audio-video cable.

please help!
and thanks!

LP

Posted by: Lp at June 16, 2009 7:26 PM

ATI's Radeon X1950 PRO video card includes composite, s-video, and component video connections for analog signals.

Posted by: Hammad at July 4, 2009 10:55 AM

Just managed to connect my laptop to new wide screen tv with s-video, and got color. My problem is that I can´t get it to display anything but the selected wallpaper. I can not see any icons or the mouse or anything but the wallpaper that is on the laptop. Please advise?

Posted by: Tom Cochran at July 26, 2009 5:41 PM

Hi i have a problem I dont have a s-video on the back of my computer but my tv does how do I hook it up?

Posted by: drew at July 29, 2009 5:30 PM

pls i dont simply understand how i can connect my TV as a second monitor, pls can you express the full details about how i can connent the TV to the CPU

Posted by: gbenga at August 25, 2009 3:19 AM

Hi Can i get support of readily available units to connect mt CPU output for CRT monitor to my normal color TV set

Posted by: Mrugesh N. Goriwale at September 4, 2009 10:34 PM

Guys, you will love this.... your digibox that you use 4 watching freeview t.v.? check the back to see if it has an rs323 input, I have a cheap one from the supermarket, cost 15 pound and my laptop plugs straight in with a cable that cost 3 pound!

Posted by: s. wilkins at November 3, 2009 3:40 PM

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