tv-out black and white s-video

[Sparky]

"doobrie" <doob...@DELETEyahoo.co.uk> wrote in message
news:MPG.18b2477af...@news.gradwell.com...
> can someone point me in the right direction with this one please?
>
> using an ati 7500 radeon, has s-video tv-out - using it with my toshiba
> portable tv it works fine - picture in colour - everything fine - when i
> plug it into an older sanyo 25" tv i get only a black and white picture -
> this is using the same cables
>
> the cabling is (from pc > tv) s-video converted to composite converted to
> scart ... and works fine with the portable but only black and white
picture
> on the older tv
>
> any idea's?
>
> as it works with the portable the cables seem ok, could it be a pal/ntsc
> thing? ive seen a few sites recommend a correctly wired s-video > scart
> convertor but as it works with the one tv not sure this is the problem -
> but i dont really know much about tv standards, etc. appreciate any help
or
> pointers.

S-video carries luminance and chrominance channels separately. Sounds like a
dodgy connection on your second TV where the chrominance path is open
circuit (assuming your cables are fine). Alternatively perhaps the TV socket
pins do not follow the s-video standard if it is a very old TV. Are you sure
its s-video?

[~ MArky MArk ~]

"Sparky" <nit...@not.net> wrote in message
news:b2air5$oc$1...@helle.btinternet.com...

> S-video carries luminance and chrominance channels separately. Sounds like
a
> dodgy connection on your second TV where the chrominance path is open
> circuit (assuming your cables are fine). Alternatively perhaps the TV
socket
> pins do not follow the s-video standard if it is a very old TV. Are you
sure
> its s-video?

That was the problem I had connecting my girlfriend's TV to the S-Video out
on her laptop. In the end I used one of these things to convert the signal
to a composite one;

http://www.laservision.co.uk/s_video_adaptor.htm

Hope this helps,

MArk
~~~~

[~ MArky MArk ~]

> the larger tv is a few years older ... could it be the video card
> outputting ntsc and whilst the newer portable accepts it the older tv cant
> cope with it?
>
> do you get black and white when outputting ntsc to a pal only tv? - tv
> protocols are a mystery to me at the mo! ;)

Also had that problem - her telly doesn't do NTSC, so image was in B&W at
first. Had to set the card to output PAL instead of NTSC then all was fine
(in colour). Unfortunately her settings don't stay put, so she has to reset
it every time she reboots (if she wants to watch a DVD on the TV at least).

HTH,

MArk
~~~~