[mythtv-users] tv-out black and white only

[David Watkins]

> My former TV-set was connected via composite video: 3 rca-plugs into the
> front.
>
> The "new" one only has scart input on the rear, so I used an adapter to
> plug in the 3 rca-plugs into the adapter and that into the tv-set.

I'm with you so far - and I think you''ve now committed yourself to
composite video, whatever you do at the other end of the cable.

> On the frontend I use the yellow S-video output and an adapter from
> audio jack two red/white RCA plugs.

A bit confused now.  Do you mean a yellow composite RCA output, or
some octopus like adapter from some DIN socket?


> My mythfrontend boots gentoo via PXE and comes up fine, I see colors
> when the init-scripts start up (those little [ok]s).

That's encouraging.
>
> The frontend itself is old hardware as well and uses a Nvidia GeForce2
> MX/MX 400 for tv-out. This worked fine for years now (until the very
> moment the old tv-set blew up yesterday ...)
>
> But now I don't get colors within X/mythtv. I tried some different
> cabling (there is an S-video out on the card and an S-video input on
> that adapter, I have a s-video cable and another adapter from the yellow
> RCA to S-video ....)

When your graphics card outputs an S-Video signal it removes the
colour information from the composite video line and sends them down
additional wires which, as I understand it, you're not feeding into
your TV.


What might be happening is that, when your computer boots it outputs a
composite video signal to your TV, which displays in colour.  When you
start X-Windows the output changes to S-Video and, because you don't
have a full S-Video cable, the colour information is lost.

I don't understand, from looking at your xorg.conf, why this would be
so, because it appears you are configured to output composite video.
You could look in /var/log/X.org.log  (or whatever) for clues.

Are you sure the TV accepts S-Video signals?  If so you could try
using an S-Vdeo to SCART lead, otherwise I'd investigate your xorg
configuration.

You could also investigate whether your TV's AV input is switchable
between S-Video and composite.  Maybe there's some auto-sensing going
on there.

Good Luck.