Cabling Mystery,How is it working with no input??

Discussion in 'Blu-ray & DVD Players & Recorders' started by dekoded, Jan 1, 2005.

  1. dekoded

    dekoded
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    I have a cabling enigma! after setting up my dvd recorder I can now record from scart AV1 input even though that socket is what I use as the output to my TV via my DVD player and STB using scart cables. :confused:
    (see diagram)

    What I find even more confusing is that when I record through this socket it appears to be in RGB as the quality is better than when recording from the dvd recorders internal tuner :confused:

    I can only assume that the video signal can pass both ways down the same cable, but if anyone can shed some light on this I would appreciate it. To confuse things even more this dvd recorder is not supposed to record an RGB input which is the reason for my complicated cabling, as I was trying to keep as many sources in RGB to my tv's single RGB scart input, and using my stb as a signal switcher which doesn't seem to have any noticable affect on the picture.
    TV- PHILIPS 28" WS
    STB- PACE TELEWEST
    DVD PLAYER- PIONEER DV565
    DVD RECORDER- LG DR4810
     

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  2. gilera

    gilera
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    I guess you must have tv on to record from av1.
     
  3. hornydragon

    hornydragon
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    Composite is what you are getting... (for Cable and TV channels) SCART is Bi-directional for Composite and audio RGB and S-video is one way only
     
  4. jimsan

    jimsan
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    Yup, Johnnie. As 'HornyD' says, you are back recording a composite feed from your TV. If the TV was off it wouldn't do this. It is, however better than the recording from the units internal tuner as this is most likely a terrestrial tuner which is inferior to the STB output.

    Jimmy
     
  5. eddyad

    eddyad
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    This is the route for 'Direct TV' recording.
    It doesn't work if the TV is getting its signal from AV1, for example when you are using a scart 'through' function on the DVD machine to feed the TV from an external source, usually done to get RGB for recording.
     
  6. dekoded

    dekoded
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    Well that sort of makes sense, however it doesn't make a difference whether the tv is switched on or off, I confirmed this by turning off the tv and then recording for 30 secs, then switched tv back on and played back recording which was fine.
    I also have an RGB only 'sqart' between the STB and the tv so the signal can only travel one way, to the tv.
    The composite signal must then be travelling back from the stb through the dvd player and into the 'output' scart connecter on the dvd recorder.
    that's probably what you have been trying to tell me but until I sat down and thought about it I was totally baffled :suicide:
    What surprises me is that the picture seems better this way rather than connecting a scart from the stb to the input scart on the dvd recorder :rolleyes:
     
  7. JethroUK

    JethroUK
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    since your mystery is now unravelled - i have a question - i noticed you daisy-chained all your device to get RGB through-out

    when you want to watch your DVD recorder (at the end of the chain) - do you need to switch all the inbetweenies to correct AV socket - or does it happen automatically when you switch it on

    why dont i try it myself? - well to be honest it took me best part of a week to fit all my a/v tackle neatly into one corner & i aint goin back in there without a map & compass :)
     
  8. dekoded

    dekoded
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    I know what you mean about the cabling, mines a nightmare as well and those flat blue 'sqart' cables are great for pq but crap from a cabling sense cos they are quite rigid and always unplug themselves when you try and move any of your kit, I wish they had some sort of retaining screws like pc monitor cables!

    Anyway to answer your question, yes the picture switches automatically and as I mentioned there doesn't seem to be any negative effects on the pq. I still have to manually change source inputs on my AE p5 decoder though so it's not perfect, but it's good enough.
    The way I have it setup all three components can output rgb to the tv, the only weak link is the composite input to the dvd recorder, but as I said the picture is still very good, it's only when you study a block of solid colour, like the yellow highlight on the telewest menu, that you notice any crawling or fuzziness, and I'm pretty fussy when it comes to pq. :smoke:
     
  9. eddyad

    eddyad
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    Were you recording Telewest when you checked this, or was it by chance the LG terrestrial tuner?

    Are all the scarts labelled RGB in your diagram 'RGB only'?
    If so, I would think you cannot be recording by the route described - but I'm not sure which connectors are omitted in RGB only scarts.

    Have you checked that you do have RGB only scart(s) with a continuity meter if all the pins are present in the plugs, or are some pins physically absent?
    If all the pins are there and you have a means of checking continuity you could check which pins are connected.

    Here is a full scart pin spec (excluding s-video)
     

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  10. dekoded

    dekoded
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    The cable between the stb and tv is an rgb only scart, which only has rgb pins and rgb earth pins connected, I don't think this makes any difference as the composite signal is travelling the opposite way to the rgb signal, from the stb through the dvd player and into the scart output socket on the dvd recorder.

    At first I didn't know this was possible, especially as I have set the output of the stb to RGB!, and when I change this to composite I no longer get a picture when viewing telewest via the dvd recorder, BUT , I tried recording telewest display setting menu whilst watching and then changing the output option from RGB to composite, when I did this the tv went blank as soon as i selected composite and reappeared when I 'blindly' switched it back. However when I played back the recording it had captured the whole recording, I could see the menu changing from rgb to composite but it had no effect on the capture :confused:
     
  11. dekoded

    dekoded
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    Just to clarify, only the scart from the stb to tv is RGB only,the other two are fully wired THOR scart leads.
    So either the stb outputs both composite and rgb at the same time or there is another type of signal from the stb reaching the dvd recorder. I'm still confused
    :confused:
    What I do know is that wen I press the TV/DVD button on the dvd recorder remote you can see the difference between the RGB signal and the 'other' signal which although still good, has some 'crawling' on the colours which does suggest a composite signal.
    I'm going round in circles here and can't figure it out, I'm sure someone has an explanation, is there another LG DR4810 dvd recorder owners out there? if so how are you connecting yours up?
     
  12. hornydragon

    hornydragon
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    RGB uses composite as a sync so you get RGB + composite on "RGB" only cables... 4 pins and 4 grounds
     
  13. dekoded

    dekoded
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    Thanks Horny, you obviously know you're stuff.
    That explains why I can get both rgb and composite outputs at the same time.

    It actually suits my situation very well as it means I can still watch telewest in rgb and also record from a single output.

    I can actually recommend the LG DR4810 if anyone was considering getting one, it would be nice to have rgb input but for £150 I think it's pretty good and the recordings are very good quality even in low quality setting.
     

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