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Discussion Starter · #1 ·
I've just gotten a Vizio "42" HD TV and connected it to my Magnavox H2160MW9A DVD recorder for the first time. The Vizio has quite a different number of video inputs, including HDMI, component video, composite video, coax RF among others.


I have the Vizio DTV RF coax input connected directly to my comcast cable input (without the set top box). I have the Magnavox connected via a new HDMI cable between the recorder and the TV and which Vizio recommends as the highest quality connection between the TV and a DVD recorder.


I also have the Magnavox connected to the Vizio through the component video input (labeled AV on the Vizio) using a standard RCA plug. This is the same way I had the Magnavox connected to my old crt TV. The video input to the Magnavox is via RF coax connected to the same Comcast cable input as the DTV input on the Vizio (again, no set top box in use at the moment).


The system is not yet configured for full HD use (it still needs a replacement HD set top box from Comcast). Furthermore, I have not yet connected my existing Comcast cable box into the mix...I have wanted to debug this initial arrangement first. Both the TV and the Magnavox are receiving cable signals via their QAM tuners right now.


The TV picture using the DTV RF coax cable input is perfect (albeit not yet HD...obviously I didn't expect HD at this point in the installation yet).


Right off the bat, I noticed a problem with the picture using the HDMI input from the DVD recorder however. Many...but not all...channels display a thin line of noise (or snow) the entire width of the picture and at the very top of the screen. This problem occurs whether I am playing programs from the affected channels that were recorded prior to connecting the recorder through the HDMI cable or whether I am playing programs being received directly through the Magnavox tuner.


On the other hand, if I switch the Vizio to the composite video (which uses the single RCA jack for video and two additional RCA jacks for audio), the line of noise disappears on all of the channels on which it had previously appeared. Furthermore, the overall picture quality immediately improves once switched to the composite AV video input. The volume of the sound also improves as well, once switched to the AV input.


I tried using a different HDMI cable (in case the first one was defective) and I also tried using a different HDMI input on the TV. Neither made any difference in the problem. I've also tried disconnecting the composite video connection from the recorder leaving the HDMI cable as the only connection between TV and recorder. That made no difference either.


Does anyone have any idea what might be going on here? Both of the HDMI cables I tried are brand new and have a good reputation on Amazon http://www.amazon.com/HDMI-meter-foo...0727687&sr=8-1 . Nevertheless, could my problem lie within the cables themselves? Do I need different HDMI cables? If so, any recommendations?


Obviously, I can make the problem go away simply by using the AV input from the recorder instead of the HDMI input but I'd like to get this figured out before I switch to full HD use.


Thanks in advance for any feedback.
 

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There is nothing wrong with your system. What you are seeing is an artifact of the NTSC (old analog TV) system. The top scan lines were used to transmit various data and were not meant to be displayed. With the ATSC (new digital TV) system, data is transmitted differently and all lines are displayed. The noise you see is from the program source. For more info, do a search in the forum on VBI.
 

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Quote:
Originally Posted by Colm /forum/post/17030205


There is nothing wrong with your system. What you are seeing is an artifact of the NTSC (old analog TV) system. The top scan lines were used to transmit various data and were not meant to be displayed. With the ATSC (new digital TV) system, data is transmitted differently and all lines are displayed. The noise you see is from the program source. For more info, do a search in the forum on VBI.

What the OP is seeing is the closed-caption data carried in the vertical blanking interval. It almost certainly means the overscan on the TV is set incorrectly. many Tvs have a "pixel mode" or "just scan" setting which shows 100% of the pixels on the screen. This is OK for computer-generated sources like video games, or even for most DVDs. But for TV sources, even those delivered by ATSC, the overscan needs to be set around 4% to allow for the various conversions and timing errors.
 

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Yes, the TV is not doing overscan on the HDMI input, but apparently is doing it fine when using the RF input per OP. The TV is assuming that HDMI will deliver exactly what is to be displayed. I think this issue with some or all Vizio TVs has been discussed before in this forum. Don't recall if there was a convenient way to get overscan on HDMI.
 

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Discussion Starter · #5 ·
Thanks for the responses. Based on your responses, it seems as if it is a non-issue. This is because presumably the problem would not occur if the signal from the recorder is coming from a DVD instead of a tuner. At all other times, I can simply use the TV's AV composite video input for the recorder signals (where the problem does not occur).


True HD broadcast signals would not be coming through the recorder HDMI input in any case. They will always be coming directly from a Comcast HD equipped set top box attached directly to a different HDMI input on the TV.
 
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