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Tell it to me straight (please!) - is this normal?

Discussion in 'General TV Discussions Forum' started by Zaichik, Jul 5, 2004.

  1. Zaichik

    Zaichik
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    I've had my new (and first) widescreen TV set for a couple of weeks now and have had various issues with the picture. Most of them have been ironed out; however two "features" remain and I haven't been able to establish whether they are to be expected, or whether there is a problem. So, I would be grateful for views on whether the following are normal on modern TV sets:

    1. Vertically scrolling end credits etc. - when these scroll on to the screen at the bottom, it looks like they are curving out of the picture, and when they move off the screen at the top, it appears as though they are curving back in again. The effect is as though they are wrapped around a drum which is being turned to move them, and you can see them moving over the apex. This may be what is happening behind the scenes, but should I be seeing it on my screen? If not, which setting in the service menu (if any) do I need to adjust to rectify this problem?

    2. Screen shape - playing around in the service menu has enabled me to straighten the vertical bowing to some degree, but there does not appear to be any way to get it completely straight in all aspects. There also appears to be no way to straighten out horizontal bend. The engineer who came to look at my set said this is normal, but to me it seems silly that manufacturers make a big deal out of tube having straight edges when you can't get the picture itself similarly straight. I find it annoying to watch a 4:3 image which is distorted out of shape, even by a small amount. Am I expecting too much?

    Thank you for your help. Sorry to be labouring these points, but I am new to large TVs and I want to make sure that what I've bought is working as it should.
     
  2. Wayne Moule

    Wayne Moule
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    It is normal and to be expected to some degree.

    Tweaking in the service menu should help, or replace it if it's that bad.

    Which make/model is it?
     
  3. Zaichik

    Zaichik
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    Thanks for your reply.

    The TV is a Panasonic TX28DTX10 100 Hz IDTV. Lovely picture (once you find the right colour/contrast/brightness settings, which are annoyingly reset when you access the service menu) and little or no motion blurring, but moving from a 17" 4:3 set to this has been a bit of a culture shock, hence my myriad of questions.

    Are you saying that both the phenomena I described are normal? Which setting in the service menu would I need to adjust to compensate for the curving credits?
     
  4. Wayne Moule

    Wayne Moule
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    To a degree, yes.

    I'm not familar with the Panny service menu, but an engineer can do this for you and if you're still not happy, get a replacement.

    I'm sure if you do a search or someone on here should be able to help with the service menu, but you could mess things up big time.
     
  5. Zaichik

    Zaichik
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    I'm wary about calling out an engineer. This is a new model and the engineer that came out last time was completely unfamiliar with it and was therefore pretty useless. I had enough of a job persuading him to make any adjustments.
     
  6. GalacticaActual

    GalacticaActual
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    Ok.
    I have a loewe nemos 32" tv.
    I have had two of these. Both of them have the same problem as your panasonic with it looking like there is some form of distoration on the sides of the screen even if the image is a wide screen one or 16;9 as it is called. I have found that adjusting h-amp and v-amp in the service menu has go some way towards rectifing this BUT IT WILL NOT CURE IT. also by adjusting the v-amp and h-amp so that the distoration is not as bad effects the over scan of the picture and you may find that you loose a little of the picture in the adjustments.
    Also before you make any adjustments, wright the original settings down first. you can do a lot damage if you are not sure what you are doing, trust me I speak from personal experince ;)
     
  7. Zaichik

    Zaichik
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    Warning noted! :rolleyes:

    So far, I've only adjusted the v-amp, h-amp (to correct an adjustment that the engineer made which led to the edge of the picture being visible in 14:9) postion and corner settings slightly. I can't imagine that I could do much damage with those! Most PC monitors have them open in their setup menus.

    However, I've stayed away from other settings, such as angle, bow and one other which the engineer did not recognise.

    I have no idea what the original settings were - I thought the engineer was writing them down before he changed them, but he wasn't. I do know that a lot of them varied considerably from the suggested settings in his service menu guide.

    I'll think about whether or not it's worth playing around some more.
     
  8. Tight Git

    Tight Git
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    Zaichik,

    With due respect to earlier contributors, the vertical distortion (scrolling credits) that you are experiencing is NOT normal.

    Vertical scanning circuits for 16:9 are virtually the same as those in 4:3 sets and they've been around as long as me (well, almost!).

    Unless there is an actual fault, the vertical linearity should be perfect (within reason).

    You should be able to adjust this in the Service Menu.

    Your other (horizontal) problem goes with the (widescreen) territory, as they say.
     
  9. Zaichik

    Zaichik
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    Can you suggest which settings in the service menu I should try adjusting? I really don't want to screw this up. I'd get an engineer to do it, but, as I said, the last engineer that came knew little more about it than I did!
     
  10. Tight Git

    Tight Git
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    Well, when I was a lad, and a Mr J.L. Baird personally delivered the TV, you just looked round the back for a knob labelled "Field Linearity". :laugh:

    Ah, those were the days...

    Now alas, it's all in the control software (an improvement I'm told), so I'm afraid it's all got a bit beyond TG. :suicide:

    Sorry.
     
  11. GalacticaActual

    GalacticaActual
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    Right let me see if I can help at all.

    On further inspection this afternoon I found the following.

    I do not have a problem with things curving of the screen top to bottom so this may be a fault with the your tv. However..........Left to right i do have this problem. If I adjust the h-amp setting and stretch the picture outwards slightly the effect is reduced. I can make it go away completely, but using the over scan test pattern on digital video essentials, you have to put it past the 5% safe action line and so loose some of the picture in widescreen mode :mad: . I have now come to an adjustment that just shows the 5% lines on the side of the picture and reduces the curving effect but it does not go away. :thumbsdow

    All I can say is try this and see what happens. Also if this worked on left to right try adjusting the v-amp so the picture stretches top to bottom and see if you can eliminate the other problem. Again it may or may not work.

    I must just say that wide screen tvs and plasmas and rear projection displays all have there various problems so if you can not put up with your problem and want to exchange the tv for some thing else, you may have quite a hunt or your hands :laugh:
    I went through a 36" sony that had very good goematry but problems with r.g.b
    A thoshiba 36" picture frame that had very bad left to right geomatry, so much so that the picture looked like it was sagging down to the middle of the screen.
    A panasonic pd36" ( dont even get me started on that one :thumbsdow :thumbsdow
    And now 2 loewe nemos 32an. Both of which had similar problems. ie picture distortion ,geomatry errors and dirty picture syndrome.
    I am gona put up with this untill christmas and then try and find a half decent plasma :suicide:
    (got to get the kitchen and bathroom done first :D )
     
  12. Zaichik

    Zaichik
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    Thanks, mate. I was wondering if v-amp was the one. :thumbsup:

    I think I've got a bit of slack that I can afford to lose as on one or two channels, you can see the edge of the picture. I'll try pushing it up a few notches and see if it helps.

    I'm not sure this is bad enough to make me return the TV - it's only really visible with credits and other scrolling text. It seems there are worse problems I could have. It is nevertheless shocking that my Hitachi 17" TV, which I paid £170 for 12 years ago outperforms a TV that some shops are selling for £700.

    Thanks to TG and Mr Moule for your help.
     

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