# Digital Cable TV Signal Missing Red? Possible? **URL:** \ **Category:** Factual Questions\ **Created:** [April 10, 2010, 4:15pm UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645 "2010-04-10T16:15:58Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [April 10, 2010, 4:15pm UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645/1 "2010-04-10T16:15:58Z")
My dad called this AM-his 52" flatscreen TV was acting up. The colors were all dark and blue tinted-obviously the red component was missing. I was all set to call the mfg.-but then an hour later, things were fine. Can a digital TV signal all of a sudden miss the red? Or is there something wrong with his set? ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [April 10, 2010, 4:22pm UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645/2 "2010-04-10T16:22:00Z")
The set can have an intermittent failure in the part that processes the red signal. The other is possible too, but in that case lots of folks would have complained. The intermittent failure is probably not “all better” now. It will most likely fail again, for longer, and eventually permanently. I know, because I had a TV for a while that didn’t get green. Tris ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 10, 2010, 4:30pm UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645/3 "2010-04-10T16:30:18Z")
First thing: check the connectors on both ends of the cable that connects the set-top box and the TV. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [April 10, 2010, 9:09pm UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645/4 "2010-04-10T21:09:02Z")
> [@commasense](#): > > First thing: check the connectors on both ends of the cable that connects the set-top box and the TV. That would only apply if he is using RGB analog component video which would be unusual and not an HDMI connector or a YPbPr analog component video. RGB component video is an analog signal with separate red, green and blue signal. An HDMI cable is digital and the colors aren’t separate. YPbPr component video don’t separate the colors either. [http://en.wikipedia.org/wiki/Component\_video](http://en.wikipedia.org/wiki/Component_video) ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 10, 2010, 9:23pm UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645/5 "2010-04-10T21:23:54Z")
Good point, but a bad connection can cause strange image problems and is both a likely problem and an easy one to fix. ---
**Author:** ![Flymaster](https://avatars.discourse-cdn.com/v4/letter/f/c4cdca/32.png) [@Flymaster](https://boards.straightdope.com/u/Flymaster)\ **Post date:** [April 10, 2010, 9:34pm UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645/6 "2010-04-10T21:34:04Z")
> [@JoelUpchurch](#): > > That would only apply if he is using RGB analog component video which would be unusual and not an HDMI connector or a YPbPr analog component video. RGB component video is an analog signal with separate red, green and blue signal. An HDMI cable is digital and the colors aren’t separate. YPbPr component video don’t separate the colors either. > > [http://en.wikipedia.org/wiki/Component\_video](http://en.wikipedia.org/wiki/Component_video) YPbPr certainly does separate the colors. The red cable (Pr) carries the difference between the luma (black and white) intensity and the red channel. The blue cable (Pb) carries the difference in blue and the luma, and the green cable (Y), carries the luma. Green can be deduced by subtracting the other two values. So, it doesn’t completely separate out the channels in the way that SCART does, but red is certainly affected by a cable, which, if loose, can really screw up the redness of the picture. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [April 11, 2010, 2:50am UTC](https://boards.straightdope.com/t/digital-cable-tv-signal-missing-red-possible/535645/7 "2010-04-11T02:50:59Z")
> [@Flymaster](#): > > YPbPr certainly does separate the colors. The red cable (Pr) carries the difference between the luma (black and white) intensity and the red channel. The blue cable (Pb) carries the difference in blue and the luma, and the green cable (Y), carries the luma. Green can be deduced by subtracting the other two values. So, it doesn’t completely separate out the channels in the way that SCART does, but red is certainly affected by a cable, which, if loose, can really screw up the redness of the picture. I stand corrected. It does look to me that if the Pr cable was messed up, then the green would also have a problem. Most of my experience with this kind of problem is with VGA cables where you can lose one color signal without causing a problem on the other two. [http://en.wikipedia.org/wiki/YPbPr](http://en.wikipedia.org/wiki/YPbPr)