# Connecting PC to TV



## Joanna K (Jul 30, 2007)

I may be making this more complicated than it is, but I need some help in connecting my PC (an IBM Thinkpad) to a Sharp LCD HDTV. My question is what kind of connecting cables do I need? The Sharp manual talks about a RGB or DVI connection to the PC while my laptop says to connect to the S-Video port. I'm confused and would appreciate any guidance. Also, are there adjustments I need to make to the display resolution or other settings to make the TV work?


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## cwwozniak (Nov 29, 2005)

Hi Joanna K, and welcome to TSG.

Does your computer have a 15 pin VGA connector for connecting an external computer display monitor or projector?

If so, does the Sharp manual say that the RGB inputs will support using them connecting to a PC?

If your laptop only has an S-Video connector for any kind of video output and your TV does not have an S-Video input connector, you will need some type of video format scan converter box to go between the PC and the TV. However, a good scan converter can easily cost more than a decent sized computer monitor that does not need a converter box.


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## Joanna K (Jul 30, 2007)

Thanks for responding, Chuck, and thanks for the welcome. 
So I checked further and it looks like I have a VGA connector on the computer, and an S-Video connector on the TV. 
My Sharp manual doesn't say much. It just shows a diagram of 2 different connections: 1) from a DVI connector on the TV to a DVI terminal on the PC using a DVI cable and 2) from a DVI connector on the TV to an analog RGB terminal using an RGB/DVI conversion cable (+ both show a 3.5 mm stereo minijack cable for audio). 
So, is RGB the same as VGA? Does it sound like there are 2 ways I can connect these, using the S-video or the VGA connector? If so, is there any reason one is preferable over the other? 
Joanna K


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## cwwozniak (Nov 29, 2005)

Hi Joanna,



Joanna K said:


> from a DVI connector on the TV to an analog RGB terminal using an RGB/DVI conversion cable


I suspect that your Monitor's DVI connector may be DVI-I that includes both digital and analog RGB inputs. Do you have specifications for the RGB/DVI conversion cable? If it has a 15 pin VGA plug then I would say that you have a good chance of getting your TV to work off the VGA output of the computer. You would just need to try to match an available video setting in the PC's video controller to the supported video formats on the TV.



Joanna K said:


> So, is RGB the same as VGA?


VGA used to mean 640x480 resolution computer video. However, VGA connectors are now be used to output much higher video resolutions. They are all RGB video. However, not all RGB inputs to a TV would necessarily be compatible with RGB outputs from a PC. I hape that is not too confusing.  



Joanna K said:


> I can connect these, using the S-video or the VGA connector? If so, is there any reason one is preferable over the other?


Typically, the RGB output from the VGA connector would give you much better video quality than S-Video. S-Video encodes the separate RGB color information into two analog signals that represent the brightness of the picture (what you would see on a black and white TV) and the other is the Hue and Saturation of the color in the picture (in broadcast TV, those two signals get further encoded into a single composite color video signal sent to the modulator in the transmitter). The TV then needs to decode the two signals back into RGB to operate the display. A lot of picture sharpness and color detail can get lost in the process.


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## Joanna K (Jul 30, 2007)

I got side-tracked and just got back to this PC to TV project. 
Chuck W., thanks a million for your help -- I finally got the right cables and I'm up and running! I'm impressed with this web site so far, and I certainly have other technical questions to ask!
--------------
Joanna K


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## Cincy2007 (Sep 26, 2007)

So what were the "right cables" to connect your PC (RGB connector) to your Sharp TV (with DVI-I) connector? Thanks!


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## cwwozniak (Nov 29, 2005)

Cincy2007 said:


> So what were the "right cables" to connect your PC (RGB connector) to your Sharp TV (with DVI-I) connector? Thanks!


I would think that the correct cables would either be A) a cable with a 15 pin VGA plug on one and and a DVI-A plug on the other end -OR- B) a VGA cable with VGA plugs on each and plus an adapter block that has a VGA socket on one end and a DVI-A plug on the other.

*Example of Cable for Option A:*
6' DVI To VGA Analog Flat Panel Display Cable
http://www.newegg.com/Product/Product.aspx?Item=N82E16882203022

*Example Cable and adapter for Option B:*
DVI ( 24+5 ) Male to VGA HD15 Female Adapter
http://www.newegg.com/Product/Product.aspx?Item=N82E16812119041

Super VGA Home Theater Cable
http://www.newegg.com/Product/Product.aspx?Item=N82E16812123086


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## JohnWill (Oct 19, 2002)

Actually, You can't convert VGA, which is analog, to DVI, which is digital with a cable. The DVI to VGA cables go the other way, DVI to VGA.


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## ericvonk (Oct 4, 2007)

i was following someone else's thread...didn't help me. I have IBM laptop T20 with Svideo output plug, and same input on HDTV. But what do I have to do to "redirect" the output from the laptop, to the TV?? I want to watch downloaded movies on my HD big screen. Help??


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## cwwozniak (Nov 29, 2005)

JohnWill said:


> Actually, You can't convert VGA, which is analog, to DVI, which is digital with a cable. The DVI to VGA cables go the other way, DVI to VGA.


No conversion other than connector types was being suggested. The whole signal path is analog video with simple digital H&V sync.

AFAIK, a display with a DVI-I input connector (as I suspected was in Joanna K's case) supports both analog and digital inputs (not at the same time). A display device with a DVI-I socket will accept a DVI-D, DVI-A or DVI-I plug. If the display device only accepts digital video, it should only have a DVI-D socket on its input. A DVI-A or DVI-I plug will not mate with a DVD-D socket. The DVI-D and DVI-I specs break down a bit further into pinouts for single and dual digital channels but they don't affect the analog configuration details.

A cable with a VGA plug on one end and a DVI-A plug on the other end will take the digital H&V sync and analog RGB video from the computer's VGA connector and feed them into the correct digital H&V sync and analog RGB video inputs on the display's DVI-I socket.


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