Snowy picture watching cable TV thru composite input

Discussion in 'Archived Threads 2001-2004' started by Marvin, Jul 28, 2002.

  1. Marvin

    Marvin Screenwriter

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    No, that's not a poem by Robert Frost.

    Anyway, here's the situation: I have a Toshiba 50H72 and cable TV. The coax is connected to the cable box, then to the VCR, then I have a coax going from my VCR back to one of the antenna inputs on the TV. This is how I normally watch cable TV. The VCR can be on or off. (I also have a coax going directly to a different antenna input on the TV but that's not important now.)

    Also, I have an RCA video cable from the VCR to the TV. This is to the "video 1" input on the TV (there are 3 composite or S-VHS inputs). This is supposed to give a clearer picture, I presume. This input works only when the VCR is turned on.

    I'm able to watch video tapes thru this input with no problem. But when I select this input to watch cable TV, the picture - usually - is very snowy. Sometimes, if I go back and forth directly between the different inputs (i.e. selecting a number on the remote), I can get a clear picture. But usually (at least 5 out of 6 times) I get a snowy picture. And the picture's always snowy when I cycle thru the inputs one by one (on the TV or remote) rather than selecting one directly.

    Since I'm able to watch tapes (or DVDs when I tried it) thru this input, it seems that there's nothing wrong with the TV. But I was able to watch TV this way (thru the video 1 input) on my previous TV with the same VCR. And since I can sometimes get it to work by fussing with the selected inputs as described above, my guess is that the problem - whatever it is - is in the TV, not the VCR (or cable).

    This is no biggie but I'd really like to understand what's going on here, and even better, if someone can point out something that might correct this.

    Thanks for your patience (if you're still with me)!
     
  2. Marvin

    Marvin Screenwriter

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    Testing..1...2...3...
     
  3. Jan Strnad

    Jan Strnad Screenwriter

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    Sounds like you've stumped the chumps! [​IMG]
    Have you tried replacing the video cable with a new, good one? By "good" I don't mean Monster or anything super-expensive, but just something like Radio Shack's Gold series or something comparable.
    Jan
    BTW: LOL about the Robert Frost line!
     
  4. Marvin

    Marvin Screenwriter

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    Thanks for the response, Jan. Actually the first thing I tried was switching the cable; I had been using an IXOS digital cable and I thought maybe there really is a difference between a digital and video cable so I swapped it with a different cable - an audioquest 2M video cable. I may have also tried a DIY-type Canare cable I got from someone at Ebay. No change.
    So I assume it's not the cable's fault. As I mentioned, the picture is fine when I use that connection/cable to watch a VHS tape or a DVD. Very strange.

    BTW, I see someone quoted that entire poem in the After Hours Lounge...whose home theater is this I think I know..he will not see me stopping here to watch his TV picture fill up with snow..
     
  5. Brent V

    Brent V Auditioning

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    I don't know if this is what is happening for you, but I experience something similar with may satellite receiver. It can produce an output on channel 3 or an output through the s-video cable. If it is turned on and set to the channel 3 output, then if I put the RPTV on anything other then channel 3, I have a very snowy picture. However, if I put the satellite in the s-video mode, I get a clear picture. Hope this helps!
     
  6. Doug_L

    Doug_L Stunt Coordinator

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    Marvin,

    Since you've eliminated the cable as being the problem, take it one step further: eliminate the chain that you've got set up by changing from Video Input 1 to Video Input 2 (or 3). By doing this you should be able to deduce that it's either: a) Video Input 1 that's the problem (if you do not experience the same issues with Video Input 2 or 3), or b) something else in the chain, most probably within the VCR.

    If it's a) from above, then you'll probably want to take the TV in for repairs, or more likely, call a service rep and describe the problem in detail.

    If it's b), try the same setup with another VCR (your own, or borrow a friend's). Hopefully swapping them won't be too troublesome, and it will yield results.

    Good Luck.
     
  7. John-Miles

    John-Miles Screenwriter

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    Have you tried puttign a signal booster on the cable line?
     
  8. Marvin

    Marvin Screenwriter

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    John, I have a cable signal booster (where the cable first enters my house) and it's probably unnecessary. Actually I'm thinking of unhooking it to see if it has any effect on this problem or my ground loop hum. But I don't have any problems with my cable reception when I use either of the coax inputs (antenna 1 - straight from the cable outlet - or antenna 2 - from the cable outlet to the box to the VCR back to the TV). So I don't believe the problem is with my cable reception in general.

    Brent, I had suspected something like that, but my TV is at channel 3 and I don't think I can set it at a different setting for just the video 1 input. I think when I did try to change the channel it switched from video 1 to one of the antenna inputs.

    Doug, I may have tried that (switching to a different video input) but I'll try it again just in case. If that has no effect, I 'll try it with a different VCR.

    Thanks for the suggestions everyone.
     
  9. Allan Jayne

    Allan Jayne Cinematographer

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    The cable box sends the selected program out the coax cable always as channel 3 or always as channel 4 (you choose which). When the coax cable goes to the VCR, be sure you choose the same channel at the VCR using its remote.
    Then when using Video 1 to get the VCR's signal, the TV's channel selection does not matter, except on some TV's you use the channel up/down buttons to get to Video 1, Video 2, etc..
    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  10. Marvin

    Marvin Screenwriter

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    I'll revive this thread once just to update it. I bought a new VCR (not for this reason) and the results are the same; I get a snowy picture when watching TV thru the VCR's composite connection to the TV, even though tapes watched thru that connection are just fine. And as I said before, this never happened with my previous TV. So it seems as if the VCR isn't at fault.

    I also tried all 3 composite inputs on the TV (Video 1, 2 and 3) and the results are the same on each. The same thing happens if I use the S-VHS connection on these inputs. So it's not a problem with any individual input (or the cable).

    The way I figure it, since tapes play fine thru these inputs, it should make no difference to the TV what is coming thru the composite (or S-VHS) cable. Which would mean the TV isn't at fault.

    I could understand it if there was a general limitation in converting a coax input (to the VCR) into a composite (or S-VHS) output (from the VCR to the TV) but I was able to do this with my previous TV. So I'm kind of confused.

    As I said before, this isn't a critical problem; I wouldn't exchange the TV and probably not even the VCR if I knew that one was at fault. But it bothers me that I don't understand why this is happening. Does this ring any bells anywhere?
     
  11. Marvin

    Marvin Screenwriter

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    Well, I figured out what was happening. I'll write it down in case anyone else ever has the same question.

    There are 3 coax connectors on the back of the TV. The top one is fed directly from the cable outlet on the wall. This is the input for the "antenna 1" setting on the TV (channels controlled via the TV).

    The middle connector outputs this signal to the cable box (which outputs a signal to the VCR).

    The bottom connector gets the signal (TV or videotape) from the VCR. This corresponds to the "antenna 2" setting, with channels controlled by the cable box.

    As I mentioned above, the VCR is also connected to the "video 1" RCA connector on the TV and the picture is fine when I use it to watch a tape but snowy when I use it to watch TV.

    When I was taping something the other week, I tried putting the TV on "video 1" while I was watching it, as an experiment. The picture was snowy as usual. But when I played back the tape, I noticed it was snowy on the tape as well. So selecting "video 1" apparently affected the signal that was being fed to the VCR (and cable box). So the VCR was not the culprit.

    The problem is the aforementioned setup, with the middle coax connector feeding the cable box. This is the recommended setup in the TV manual and eliminates the need for a splitter. But it turns out to be the cause of the problem.

    So I attached a splitter frm the cable outlet on the wall, splitting it to the top (antenna 1) and bottom (antenna 2) connectors directly, without using the middle connector. This solved the problem! The "video 1" signal is now noticeably better than the "antenna 2" signal.

    Another problem caused by the original setup is not being able to record while the TV is off. (I found this out when a timer recording didn't work.) That's not a problem any more.

    Whether or not this was a defect in the TV, I have no idea. But as long as it's easy to get around, it doesn't matter to me.
     

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