TV-out stopped working when trying PAL-{M,N} on PAL

[Martin Ågren <martin.agren@gmail.com>]

Hi,

I was trying to set up TV-out (S-video to SCART) on my laptop (Intel
GM965/GL960 and xserver-xorg-video-intel) using

  xrandr --output TV --set TV_FORMAT PAL --mode 1024x768

and got sound ok and a clone of the laptop screen on the TV, but I
couldn't get any colours. Figuring there weren't a lot of different
properties and options to tweak, I tried some other versions of PAL,
namely PAL-N and PAL-M. Didn't work of course. But what is worse, I
can't change back to my half-working setup! I've run

  xrandr --output TV --off

followed by the command at the top of the mail, and the TV flickers a
little for a second, so some sort of signal is reaching it, but the
image is totally black. The sound doesn't work any more. The verbose
output is

  crtc 0:     1024x768   25.0 +0+0 "TV"

Running "xrandr --prop" produces

...
TV connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
        BOTTOM: 37 (0x00000025) range:  (0,100)
        RIGHT: 46 (0x0000002e) range:  (0,100)
        TOP: 36 (0x00000024) range:  (0,100)
        LEFT: 54 (0x00000036) range:  (0,100)
        TV_FORMAT: PAL
                supported: NTSC-M       NTSC-443     NTSC-J       PAL-M
                           PAL-N        PAL
   1024x768       25.0*
   800x600        25.0
   848x480        25.0
   640x480        25.0

I've restarted X (and the TV...) and tried re-issuing commands,
googling, etc. and am at a complete loss at what to try next. I don't
have a DVD player or similar, or I would make sure that I haven't
bricked the TV during my experimenting, but this seems far-fetched. I
really hope there is something somewhere that needs resetting. Does
anyone have any idea on how to at least get back to the half-working
state?

Thanks,
Martin