TVs & Home Theaters forum

General discussion

Sound quality poor with Comcast cable box and Sylvania Plasm

My mom-in-law just purchased a new Sylvania 6842 PF Plasma monitor. She has Comcast digital cable with a Motorolla DCT2000 Cable box.
When the TV is hooked up directly to a DVD player or VCR without the cable box hooked up at all the picture/sound is perfect.

Once the cable box is hooked up directly to the TV or to the TV through the DVD player there is a loud humming in the background of the sound and also a horizontal line that slowly scrolls from the bottom up.

Connects are with a brand new set of RCA cables. Tried S video for the video signal and same problem occurs with the scrolling horiz line.

Can anybody tell me if there is a compatibility issue with the box and TV? Is this electrical interference that can be solved with some type of filter?
I don't have Comcast cable, will they upgrade the box for no charge if this is a compatibility issue between the box and TV?

Thanks in advance for any assistance.

Discussion is locked
You are posting a reply to: Sound quality poor with Comcast cable box and Sylvania Plasm
The posting of advertisements, profanity, or personal attacks is prohibited. Please refer to our CNET Forums policies for details. All submitted content is subject to our Terms of Use.
Track this discussion and email me when there are updates

If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.

You are reporting the following post: Sound quality poor with Comcast cable box and Sylvania Plasm
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.

Popular Forums

icon
Computer Newbies 10,686 discussions
icon
Computer Help 54,365 discussions
icon
Laptops 21,181 discussions
icon
Networking & Wireless 16,313 discussions
icon
Phones 17,137 discussions
icon
Security 31,287 discussions
icon
TVs & Home Theaters 22,101 discussions
icon
Windows 7 8,164 discussions
icon
Windows 10 2,657 discussions

SMART HOME

This one tip will help you sleep better tonight

A few seconds are all you need to get a better night's rest.