My DELL INSPIRON 6400 Laptot has a 7 pin s-video out put & TV has only AV in plugs.How can I use S-video cable

The way u have connected it is correct.

7-pin svideo on laptop to RCA in on ur TV.

Here r a few things u might want to check.

1.U did connect to av-in & not av-out.

2.If ur TV has multiple av-in check u selected the proper one

to display.

3.In ur Laptop u must set the display to dual mode which ever

type u want.(usualy it is done from ur graphics controller)

First of all you don't have to "enable" s- video on your TV. It is just a connection and switching to "input" "input2" "auxillery" or station 3 should allow you to recieve picture from any AV/S-Video/Coaxle/or auxillary Connection. As for a way around your AV input and S-Video Output: There are cables that can be bought at your local Radio Shack that will allow you to do this. You will have to buy three parts but you will have the connection. One of the cables will have your AV connection wires and they will come together into a long cable and will have a female end on it. Another piece will be to your S-Video output connection on your computer and will also have a female end on it. The third is a bridge that will connect the two wires and will have two male ends butted opposite. I know that this setup works - I've done it in the past, but the only difference was that I ran it through a VCR with AV from a computer with S Video. To activate it from your computers side, you should just have to press "FN + F8" or whatever is the equivalent to switch the monitor. I would also check your Radeon or Nividea software to make sure that there is not a setting preventing this. You may just need to check a box and this is usually not a problem. I hope this helps. Your cables can run between 20 - 50 dollars depending on the quality and length of wire. If you explain to them what you are doing the can help.

Plug in the s-video cable before you change the settings.

The computer automatically senses if you have an s-video cable plugged in.

srry to tell you but s-video is 480p and a/v cable is less i think 280 or sumthing an older tv no way to work right

google it..............no really you can get a converter