1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Panny 6 interference problem?

Discussion in 'Plasma TVs' started by apgr, Oct 18, 2003.

  1. apgr

    apgr
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I have recently got myself the new Panny 6 plasma :). I am delighted with it. I do see some colour banding on Sky+, but overall the picture is stunning.

    I do however see a subtle problem, which I suspect is mains pickup somewhere in my set-up. Occasionally I see a fine line structure. The lines are separated by about half an inch and tilt about 30 degrees backward of vertical - similar to a \ . The problem is subtle and not always there - when it does come, it is almost as if it is a modulation of the underlying noise in the image.

    I suspect this is mains interference: One Christmas I brought the digital projector home from work to view DVDs :nono:. I made up a long s-video cable and saw a similar band structure but much worse. In this case I solved the problem totally by lifting the screen at one end of the cable.

    I have tried lifting the SCART lead screen on the plasma end with no effect (I am using the SCART board input at the moment).

    I have tried turning off/unplugging all the rest of my kit, but can't seem to track the problem down. My AV system is running off a dedicated spur from the mains so there are no earth loops in the power supply and all the AV kit goes into the same power strip.

    I have also tried additional ferrites around various cables with no joy. :confused:

    Any ideas most welcome!

    Ade
     
  2. NeilMcRae

    NeilMcRae
    Active Member

    Joined:
    Sep 2, 2002
    Messages:
    1,187
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    41
    Location:
    London
    Ratings:
    +6
    are you using the powercable that came with the screen?

    Neil.
     
  3. panasonic6

    panasonic6
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    What power strip are you using?
    Just out of interest.

    I am getting exactly the same problem.
     
  4. apgr

    apgr
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    The power strip is actually two wall mounted double power sockets linked directly to the mains fuse box via 30 amp wire - a dedicated spur.

    Last night I checked all my mains plugs. One seemed a bit dodgy (the one on the AMP) so I changed it. The Sky+ pictures do now seem subtly better.

    I have noticed that I can see it on DVD as well. Very low level - modulating the noise - it seems most obvious on flesh tones (which are most prone to banding in my limited experience).

    I am now 100% convinced this is a grounding problem. I guess when I get time I will keep systematically swaping things.

    One thing the Plasma forced me to do (for now) was to daisy chain my DVD player and Sky+ via SCART. SO I am now using a freebie SCART lead to connect the DVD to Sky+. I have a second fancy SCART lead but it is 3m long.

    I guess the bottom line is that in getting my system rapidly reconfigured to accomodate the PLASMA, I have taken some short cuts and am seeing the consequences.
     
  5. Gordon @ Convergent AV

    Gordon @ Convergent AV
    Distinguished Member AVForums Sponsor

    Joined:
    Jul 13, 2000
    Messages:
    13,999
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Living in Surrey, covering UK!
    Ratings:
    +2,803
    The problem you will have seen with the s-video lead was beacuse they lead was cheap and used a shared return instead of having seperate ones for Y and C.

    It does sound like an earth loop somewhere. Common sources of these probelms are aerial systems. Try disconnecting the aerial leads to see if they make it come or go. Then start systematically working through everything from start to finish. I'd start by attaching one unit at a time to the system in sequence to verify at what point the interference appears. Then you can start to read up about how to get rid of it.

    Gordon
     
  6. mrsimes

    mrsimes
    Standard Member

    Joined:
    Aug 21, 2003
    Messages:
    36
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Ratings:
    +0
    Hiya,

    I finally took the plunge and ordered a Panny 6 from NexNix.
    The first thing that I noticed when I connected the plasma, is this very same interference across skin tones.

    Does anyone else experience this? If so, how have you cured it, or do you just put up with it?

    I've played with the settings for hours and can't get rid of it, and it's really bugging me!!!!!

    Si
     
  7. daveb975

    daveb975
    Well-known Member

    Joined:
    Oct 25, 2002
    Messages:
    3,949
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    103
    Location:
    London
    Ratings:
    +270
    Can I ask what inputs you are using whn you get this problem?

    I had a similar problem when I got my Panny 6, but only on Composite inputs. The problem that you mention was visible on all areas of bright colour.

    It was happening on both my Freeview box and PS2. Once I changed the output on the Freeview box to RGB it cured it completely. It is still there on the PS2.
     
  8. apgr

    apgr
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    The problem was with the scart input.

    I have got an RGBtoComponent convertor box and all my problems have been solved.

    :clap:

    Cheers...

    Ade
     
  9. mrsimes

    mrsimes
    Standard Member

    Joined:
    Aug 21, 2003
    Messages:
    36
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Ratings:
    +0
    Hiya,

    Yes, I am using the standard Panasonic SCART input board.
    Flicking between PAL and RGB on my digibox shows a drastic difference in picture quality (RGB being the better of the two), however, even in RGB mode I get this 'interference'.

    Having searched the forum on these symptoms, I'm beginning to wonder if it is mains related, as the on screen menu from the plasma itself is pin sharp with no lines across it at all.

    I'm wondering if it's worth speaking to NexNix, to see if I can try a JS convertor box (RGB to VGA) and see if that sorts it. I'm going to borrow a laptop from work tomorrow and plug that into the VGA socket, play a DVD, and see if I still get the problem.

    This may have been asked before, but does anyone know if I will lose the 'just' aspect mode if I use the VGA input? The other half will not watch 4:3 programs unless they are in 'just' mode.

    Thanks,

    Si
     
  10. apgr

    apgr
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I use the VGA input but set to Component. The "Just" mode is still there. However the "Auto" mode which will automatically Zoom letterboxed 4x3 material does not work via this input.

    I do not find this a problem. A much bigger problem was the lass of automatic aspect ratio swiching which was solved beautifully by the new aspect ratio switcher box (see sticky poll in this forum)

    Ade
     
  11. mrsimes

    mrsimes
    Standard Member

    Joined:
    Aug 21, 2003
    Messages:
    36
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Ratings:
    +0
    Hi Ade,

    Sorry, I'm a little confused. You purchased the JS-Tech RGBtoComponent convertor?

    Therefore you must be feeding into a component board that you purchased for the plasma, and not into the VGA port?

    I'm really undecided at the moment. Do I go for a JS-Tech RGB to VGA (ie no boards required in the plasma at all), or should I change the SCART board for a component board, and buy a JS-Tech RGB to Component convertor?

    The decider for me (or the missus) will be keeping the 'just' mode. I take it the PQ should be the same via both of these methods?

    Any suggestions????
     
  12. apgr

    apgr
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Yes I have the JS-Tech RGBtoComponent convertor.

    You do not have a problem! The VGA input can be switched in software to accept component input via the same connector. This is what I have done. I did not buy the component board.

    Cheers...

    Ade
     
  13. deman77

    deman77
    Standard Member

    Joined:
    Aug 20, 2003
    Messages:
    260
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    16
    Location:
    London
    Ratings:
    +0
    I also had a problem with a scartboard+QED cable. Swapped ot for QED synch extractor and never had it again.

    I doubt it's interference, because the first part of my synch extractor is exactly the same scart cable just hardwired and it goes through the same spaghetti of mains leads and connectors behind the sub and up to the plasma.
     
  14. mrsimes

    mrsimes
    Standard Member

    Joined:
    Aug 21, 2003
    Messages:
    36
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Ratings:
    +0
    Yay!!!!!

    :clap:

    Thanks for all your help guys!
    Ade, before you replied yesterday, I made an executive decision and ordered the JS Tech RGBtoVGA convertor from Nexnix. It arrived today.
    Plugged the old girl in and WOW!
    I really couldn't believe the drastic difference in quality. I'm using the same, original SCART lead that I had plugged into the SCART board, but now it's plugged into the JSTech box. Nexnix provided me with a cheap (£8) VGA cable to go from the box to the plasma and it's absolutely great. All the 'interference' has gone and everything looks nice and sharp.

    I see the option you refer to, to switch between RGB and component on that input (all is clear now (literally!))

    Oddly, the one thing I was sure I wouldn't get was the 'just' mode. I was pleasantly suprised to find that even though the manual states it shouldn't be available on the VGA input, it IS there and it works just the same.

    So now I'm really happy cos I have great PQ and the missus is really happy cos she's still got 'just' for when she watches 'Charmed'!!!!

    So for anyone that's considering buying a Panny plasma, I would recommend not to buy the Panny scart board. Go for a JS Tech box instead!!!!!
    Thanks Dr Sim!

    Si
     
  15. Jasonjo

    Jasonjo
    Well-known Member

    Joined:
    Dec 3, 2001
    Messages:
    2,649
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    UK
    Ratings:
    +112
    great news, cheers for the Just mode on VGA feedback...dont think they updated the manual from the 5 series as this couldn't do just mode on VGA...

    JJ
     
  16. deman77

    deman77
    Standard Member

    Joined:
    Aug 20, 2003
    Messages:
    260
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    16
    Location:
    London
    Ratings:
    +0
    what's the big deal about Just mode, isn't it stretching the sides (i.e. distortion)? One of my reasons to get rid of CRT was to get perfect geometry. With Just on, niether 16:9 nor 4:3 is good.

    Aren't you content with just switching between 16:9 and 4:3? Seeing as SKY+ remote happily does that I don't see why anyone would use any other mode. In fact, Just and Zoom are just annoying extra clicks that I have to go through.
     
  17. RoyH

    RoyH
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Apgr,

    I’m intrigued by your initial post on the “fine line structure” and subsequently on the RGB to component setup.

    It strikes me that the half-inch separated lines \ you describe are those mentioned in a number of posts and publication reviews (e.g. HCC). Apparently, this slanted banding is very much a ‘feature’ of the Panasonic display which I’ve read about in many places and also observe myself on my PW6. Frankly, I’m very puzzled that other posters have not also cited this well-known banding issue.

    I use RGB throughout and the slanted banding is about the only issue that tends to niggle me on my setup. Given the widely reported banding issue and having also previously considered the possible advantages of moving to component input, I was fascinated to then read our account of the SCART input being to blame. You continue to describe the use of an RGB to component converter (specifically the JS kit) though you don’t have the component terminal board.

    Page 27 of the PW6 manual (under “Customising the Input labels”) does allow PC/COMPONENT/RGB/DVD/STB for the D-Sub connector but then I’m not at all clear on what functionality is provided/invoked by this labelling. I’ve also noted that page 8 of the PW6 manual indicates component-type signals on pins 1, 2 and 3. Does changing the D-Sub label to “Component” actually switch the input to component? Considering this D-Sub configuration and the use of the RGB to component kit, two main questions spring to my mind:

    1) If the D-Sub connector can be configured to accept component signals, why do Panasonic bother to provide a component terminal board?
    2) How do you connect the three phono connectors from the converter box to the D-Sub?

    Please forgive my ignorance on the technical details but I would be truly grateful if you’ve found a solution to the banding problem.

    Cheers,

    Roy
     
  18. deman77

    deman77
    Standard Member

    Joined:
    Aug 20, 2003
    Messages:
    260
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    16
    Location:
    London
    Ratings:
    +0
    RoyH,

    1) so that you can connect component sources with RCA/BNC terminated cables.
    2) there is two types of JS-Tech converter boxes: a) converts scart RGB to component signal (has 3phono out) b) converts scart GRB to component signal plus extracts the horizontal and vertical sync (has D-sub out).

    You can reduce banding by turning down the contrast. There were speculations that banding was the byproduct of the refresh rate doubling logic on D6 and you can get rid of it by feeding it a higher refresh rate signal, but noone actually ever conformed this, in fact I think some have mentioned that you can see banding even with PC signal. Some said that if you feed it through DVI card D6 will bypass all internal processing and will show no banding but it turns out that DVI is limited to 8bit (not sure about the number but less then Dsub) per colour and therefore is more likely to cause banding. So no real solution so far. I don't remember myself seeing (or even looking for) banding in the last 4 months which means it's not that bad at all.
     
  19. RoyH

    RoyH
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    deman77,

    Now understood - thanks for taking the time to reply.

    JS Tech are about to get another sale.

    Cheers,

    Roy
     
  20. Joe Fernand

    Joe Fernand
    Distinguished Member AVForums Sponsor

    Joined:
    Jan 20, 2002
    Messages:
    24,270
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    The Borders
    Ratings:
    +2,572
    Hello all

    I must say I've never been convinced that the TY-42TM6TB SCART Input board has been any good - we've always supplied without it where possible.

    RoyH - as you now know you can input YUV or RGBHV video signals into the HD15 VGA port on the display.

    If you want to use SCART RGB converted to YUV direct from a JS converter or use an AV Amplifier to pre select multiple YUV inputs downstream from the Plasma we (and others) supply 3RCA to HD15 cables to go between your YUV out and the Plasma HD15 for this application.

    The JS Technology RGB2VGA converter is ever so slightly cleaner than the RGB2YUV - though as described above many customers find using the RGB2YUV downstream of an AV Amp and then switching on the AV Amp is the most flexible set up.

    Your 6 Series display has three input slot plus the inbuilt VGA socket so you can populate the input slots as required - some folk may have an application that requires three or four PC's or three or four direct YUV connections hence the range of input boards.

    Best regards

    Joe
     
  21. apgr

    apgr
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Changing the label does not switch the D-sub input to compoment. However there is an option in the "signal menu" - COMPOENT IN SELECT (I think) - that allows to you toggle between VGA and Component. You only see this menu when you have a signal going into the D-sub.

    1) I think they make a componet board in case anyone wants more than one component input.

    2) I bought a cable that has three phono commenctors on one end and a D-Sub on the other.

    This set up has definitely eliminated the problem totally.

    Ade
     

Share This Page

Loading...