12.04 - I can't view my laptop on TV

I have a Compaq c770 with an Intel graphic chipset. I'm running Ubuntu 12.04. I plug the TV through a S-VIDEO port. However, nothing appears on the TV.

Ubuntu detects the TV, and I can configure it. However, the TV is still black.

When I write xrandr --verbose it shows this:

---

TV1 connected 1024x768+1280+0 (0x4b) normal (normal left inverted right x axis y axis) 0mm x 0mm

Identifier: 0x43

Timestamp: 1262326

Subpixel: unknown

Gamma:      1.0:1.0:1.0

Brightness: 1.0


Clones:    

CRTC:       1

CRTCs:      1 0

Transform:  1.000000 0.000000 0.000000

            0.000000 1.000000 0.000000


            0.000000 0.000000 1.000000

           filter: 

bottom margin: 37 (0x00000025)  range:  (0,100)

right margin: 46 (0x0000002e)   range:  (0,100)

top margin: 36 (0x00000024) range:  (0,100)


left margin: 54 (0x00000036)    range:  (0,100)

mode:   NTSC-M

    supported: NTSC-M       NTSC-443     NTSC-J       PAL-M       

               PAL-N        PAL          480p@59.94Hz 480p@60Hz   

               576p         720p@60Hz    720p@59.94Hz 720p@50Hz   


               1080i@50Hz   1080i@60Hz   1080i@59.94H

848x480 (0x49) 29.0MHz +preferred

    h: width   848 start  849 end  912 total  944 skew    0 clock   30.7KHz

    v: height  480 start  481 end  512 total  513           clock   59.9Hz

640x480 (0x4a) 22.6MHz +preferred

    h: width   640 start  641 end  704 total  736 skew    0 clock   30.7KHz

    v: height  480 start  481 end  512 total  513           clock   59.9Hz

1024x768 (0x4b) 53.8MHz *current

    h: width  1024 start 1025 end 1088 total 1120 skew    0 clock   48.0KHz

    v: height  768 start  769 end  800 total  801           clock   59.9Hz

800x600 (0x4c) 34.0MHz

    h: width   800 start  801 end  864 total  896 skew    0 clock   37.9KHz

    v: height  600 start  601 end  632 total  633           clock   59.9Hz

---

I really don't know what is wrong.