issues with cable box and tv over component

I have a 42 inch Vizio LCD(1080P).
I have a 8300HDC Scientific Atlanta DVR.

When I hook up the dvr to the tv over component horizontal lines travel up the screen. The lines are a slight distortion of shape and color.
If I hook the DVR up over hdmi everything is fine.

I have a 26inch philips(720P) when hooked up to the dvr with component it works fine.

I also have a xbox 360 which works fine with the 42 inch vizio hooked up over component.

Anyone have any idea of what the problem might be and how to resolve it?

Step #1: try again with "known good" cables. If this doesn't fix the problem go to Step #2.

Step #2: call for service.

My son had much the same issue with his cable box except there was also a hum associated with it as well. The cable DVR was allowing a ground loop and some audio cable ground loop isolators fixed the hum, but the horizontal banding persisted. Since you can't use ground loop isolators on the component cables, we switched to HDMI and its been fine since.

We did switch out the DVR to the same problem and of course Comcast blamed the TV, so service for this could be a dead end. It could be either the TV or the DVR in fact. Other TVs may not have the problem show up.

Recommend using the HDMI cable for the connection.

Yes, there is a hum, it varies volume for different channels.

It works fine over HDMI. So I guess thats what I should do.

I did have the cable company send techs to check it out. They could not figure out the problem and said I should call the tv manufacurer.

But from what you are saying, rbinck, the tv isn't defective its just some ground loop thing? I just don't want my tv to be dying and not do anything about it until the warranty is up.

Thanks for the help.

I don't think the TV is defective at all. It probably does not have the ground isolation that the SA engineers assumed all TVs would have, but my feeling is it is the fault with the SA boxes since they seem to be the only boxes that pose the problem. At least your HDMI works, the earlier versions didn't.