1. Guest,
    If you need help getting to know Xenforo, please see our guide here. If you have feedback or questions, please post those here.
    Dismiss Notice

How do you fix Overscan?

Discussion in 'Displays' started by JustinGrimball, Apr 24, 2003.

  1. JustinGrimball

    Joined:
    Jan 27, 2003
    Messages:
    22
    Likes Received:
    0
    On my tv, Panasonic 47" Widescreen HDTV Projection Monitor
    Model: PT-47WX42, the picture is a little low. When CNN has like a ticker bar at the bottom it is 1/2 cut off. AVIA said that my tv was like 3% off. How do i fix this?
     
  2. Allan Jayne

    Allan Jayne Well-Known Member

    Joined:
    Nov 1, 1998
    Messages:
    2,406
    Likes Received:
    0
    Use the height (VSIZ) and width (HSIZ) adjustments. All TV sets have screwdriver adjustments (pots) for this in the back under the rear cover, most sets with service menus have service menu adjustments for this, a few have regular on screen menus for this. If necessary, also use the positioning (VPOS, HPOS) adjustments.

    As the set ages, the menu adjustments might not stretch far enough and then the screwdriver adjustments have to be used. Most set owners should leave the latter to a serviceman, since exposed contacts with hgih voltages will be reachable when the cabinet is opened.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  3. JustinGrimball

    Joined:
    Jan 27, 2003
    Messages:
    22
    Likes Received:
    0
    how do i access service menus?
     
  4. Kevin. W

    Kevin. W Well-Known Member

    Joined:
    Oct 27, 1999
    Messages:
    1,546
    Likes Received:
    0
  5. ManW_TheUncool

    ManW_TheUncool Well-Known Member

    Joined:
    Aug 18, 2001
    Messages:
    5,945
    Likes Received:
    30
    Real Name:
    ManW
    I would not try to reduce overscan below the 3% setting you are seeing now. That's probably as low as you can go w/out serious convergence/geometry problems. From what I can gather, most people keep their overscan at somewhere between 3 - 5% for this reason. Even the highly reputable ISF guys who frequent these forum sites don't seem to go lower than ~3%.

    FWIW, I have the 53" version of that RPTV and leave it at ~5% overscan. Maybe one of these days I will venture to reduce it to ~3% (and tackle the likely resulting convergence/geometry problems)...

    _Man_
     
  6. Alan Pummill

    Alan Pummill Well-Known Member

    Joined:
    Jul 6, 1999
    Messages:
    1,264
    Likes Received:
    1
    Are you watching CNN in a stretch mode. If so, switch between the stretch mode and 4:3. Is it the same on both? I think you will see the difference!

    And I agree with _Man_. When Gregg Loewen came to calibrate my 58" Pioneer Elite, it had over 7% over-scan on it. He got that down to around 4% and told me that any less over-scan would indeed cause problems at the edge of the picture.

    Hope this helps!!
     
  7. Mark Zimmer

    Mark Zimmer Well-Known Member

    Joined:
    Jun 30, 1997
    Messages:
    4,285
    Likes Received:
    24
    What issues does it present? Does it only affect TV viewing and not DVD? I often use the scaling on my Malata player to eliminate overscan and have had zero issues on the edges other than an occasional thin white line that I can get rid of readily by just decreasing the scaling a notch--the #$%*(&^ ISF Tech refused to reduce it and when I checked it's nearly 10%---Apocalypse Now at 2.0:1 registers as 16:9 with no black bars visible. I'm assuming though that if I go in and reduce the overscan myself the whole thing needs to be recalibrated--is that correct?
     
  8. Rajeev_s

    Rajeev_s Well-Known Member

    Joined:
    Dec 20, 2002
    Messages:
    184
    Likes Received:
    0
    I have reduced overscan on my TV to 4% horizontal and 3% vertical, anything below that has caused problems with convergence and geometry. Convergence just seems to go way off below that level. And I am very happy with what I see.

    I think you can achieve overscan below that only on direct view CRTs, LCD or DLP, LCOS projection TVs. Please dont take my word on it.
    Guys correct me if I am wrong.
     
  9. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

    Joined:
    Mar 16, 2000
    Messages:
    2,909
    Likes Received:
    1
    Location:
    Calgary, Alberta
    Real Name:
    Michael Chen
    Greetings

    If you reduce overscan too much on the Panny, you might see some anomolies creep in like color reflections on the edges and such. If that happens, you need to back off on the overscan.

    Reducing overscan typically throws out convergence and geometry. This will have to be fixed up.

    Regards
     
  10. Steven Hubbard

    Joined:
    Nov 28, 2001
    Messages:
    11
    Likes Received:
    0
    Michael.

    I saw your reference to color reflections.

    I wanted to write to say that my over-scan registers at 3 on the top and on the left of my panny 53 while registering 5 to the right and on the bottom. I can see the reflections you refer to on the top of the set. It appears to be triggered by certain colors and my appear as a bluish tint or a bright white highlight.

    At one point I had red show up, but I when I corrected the geometry grid, it disappeared while limiting the remaining blue/white I described above.

    I am awaiting the Service Manual before attempting to adjust the over-scan. In the meantime I take it that I will need to go back and do the convergence. Do you recommend the "fine" or will "coarse take care of everything?

    Thank you in advance.
     
  11. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

    Joined:
    Mar 16, 2000
    Messages:
    2,909
    Likes Received:
    1
    Location:
    Calgary, Alberta
    Real Name:
    Michael Chen
    Greetings

    Coarse for grid centering and fine to fix all the little things.

    Regards
     

Share This Page