I have a somewhat strange problem with (analog) TV-out from a laptop to an old CRT TV.

When I try to connect the PC through S-Video or composite to the ports on the rear of the TV, the PC constantly (every 2-3 seconds) keeps changing resolution between what seem to be the preset resolution of the laptop LCD and the default TV resolution. It doesn't stop unless I yank the cable. Component video doesn't seem to work at all, but that may be because I'm using the wrong adaptor.

Connecting the same composite cable to the ports on the front of the TV works fine, but I'd prefer S-Video (and to have the cables out of the way).

My best guess is that the TV's rear ports aren't properly communicating to the PC that they're connected, and the PC keeps alternating between sending video to the TV-out and not sending it.

I know the nVidia control panel has an option to force output to the TV-out ports, but the laptop's graphics are Intel GMA X3100.

I seem to recall we had problems with Sky connected to this TV as well (worked through the front ports, not the rear) but that was quite a while ago. It's been connected to the aerial only for years.

If anyone has any suggestions they'd be appreciated.