I'm experiencing an odd phenominon on my home theatre setup. On both my 19" samsung LCD TV, and my Hitachi LCD projector, i'm getting these waves of colour (usually blue, but sometimes green) slowly rolling from bottom to top. I've got it all hooked up via component cables. The only thing I can think it could be is inferior cables, or perhaps some sort of interference.
Heres a breakdown of how things are hooked up, and when they have problems:

Samsung LCD TV
xbox 360 > component switcher > TV - - Fine
Playstation 3 > component switcher > TV - - Fine
HD Cable box > component switcher > TV - - BAD
Computer > TV (via RGB) - - Fine (usually)

Hitachi LCD projector
DVD > Receiver > projector - - Fine
HD Cable Box > Receiver > projector - - BAD
HD Cable box > Projector - - BAD

Cable box > SDTV (via compsite) Fine

I was trying to watch a movie from cable just now and it was rolling on me. I tried fiddling with the cables, but it did nothing. When I pulled out the green and put it back, it look good (stopped rolling) for about 1 second, then went bad.

I've already ordered a long DVI cable for HD Cable but any incite on this problem would be helpful.

Thanks

if its any more help, the anomoly is a lot more noticable when darker imagages are up.
I posted this in the projecter section because the problem is a lot worse on the projector, than it is on the TV.

your HD cable box and the PC sources seem to be the only problem components. You probably see the anomaly on your pj more because it is a bigger image. Check your cables again and make sure they don't run directly beside any power or RF equipment for a long run. It seems you're on the right track though for the new cables.

AUSSiE

Try removing the switcher from the situation just to eliminate that as a potential problem. I have a cheap pelican switcher that does not co-operate with all of my sources.

ground loop problem. Try a ground loop isolator (google may help)

I'm experiencing an odd phenominon on my home theatre setup. On both my 19" samsung LCD TV, and my Hitachi LCD projector, i'm getting these waves of colour (usually blue, but sometimes green) slowly rolling from bottom to top. I've got it all hooked up via component cables. The only thing I can think it could be is inferior cables, or perhaps some sort of interference.
Heres a breakdown of how things are hooked up, and when they have problems:

Samsung LCD TV
xbox 360 > component switcher > TV - - Fine
Playstation 3 > component switcher > TV - - Fine
HD Cable box > component switcher > TV - - BAD
Computer > TV (via RGB) - - Fine (usually)

Hitachi LCD projector
DVD > Receiver > projector - - Fine
HD Cable Box > Receiver > projector - - BAD
HD Cable box > Projector - - BAD

Cable box > SDTV (via compsite) Fine

I was trying to watch a movie from cable just now and it was rolling on me. I tried fiddling with the cables, but it did nothing. When I pulled out the green and put it back, it look good (stopped rolling) for about 1 second, then went bad.

I've already ordered a long DVI cable for HD Cable but any incite on this problem would be helpful.

Thanks

Do you have dimmer switches in the room? I have a similar issue, only when using component cables, and my projector (no problem with HDMI).

When the dimmer is used to dim up (brighter), the lines move up faster, and when dimmed down, the lines go a little slower and move down briefly.

Turning off the lights the problem almost disappears entirely. Turning back on the lights, the problem instantly returns.

I use only HDMI now though, so I don't really suffer from the problem.

Thanks for the ideas

I've further troubleshooted the problem, but to no avail.
The only transmitter of any kind is a wireless router. I unplugged it, but it had no effect. I unplugged everything else from the TV, I turned off everything in the room, but didn't effect it at all.

I'm using some long cables, including a 50' component for the projector and and 10' for the TV. Both are running near other electronics, and infront of power outlets and power-bars. Would that effect it?

I kinda hope thats not it though, because I'd have to rewire my entire room.

I read an article about ground loop. It didn't make much sense, but it said that having things in different power outlets can cause it.

I moved the TV to the same outlet as the cable box, and used a short component cable. The picture improved and the rolling nearly disapeared. I had to have a purely black image on screen before I saw any rolling.

Am I going to have to rewire me whole living room?
suggestions?

ok....further progress

I found out that if I unplug the cable from the cable box, the rolling lines stop immediatly. Thats almost definatly the problem.

So the question now is..what do I do about it? Any ideas?

Call your cable company and get a replacement cable box. It sounds like your's has failed (it has lost it's vertical sync).

Ground loop...bottom to top. Due the the ground of your cable and the ground to your home's electric is off-sync.

To test...get a "cheater" plug. A cheater plug is one of those plug that turns a 3 prong to a 2 prong. ~$0.99 at home depot or less. Unplug your projector install the cheater plug and start it up. If the roll goes away the that is it. And I believe that should do the trick.

Thanks for the suggestions.
I called the cable company and they seemed to agree that it was ground loop. They're sending someone by this week.