Black Level or White Level problem -- recommendations needed

Discussion in 'Displays' started by Jeff Pounds, Nov 5, 2003.

  1. Jeff Pounds

    Jeff Pounds Second Unit

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    I've recently noticed a problem with my TV and I'm hoping someone has some advice...

    I'm thinking I have either a black level or white level problem... possibly caused by a greyscale issue...

    Here's the deal...

    My TV is the Panny 53" 16x9 HDTV (last year's model)...

    Recently, I've noticed that I seem to be losing shadow detail and movies that have an especially dark look seem even darker than normal.

    So I went in and re-did all of my video calibration tests in Avia (at night, no lights...), I noticed that on the black level (brightness) test that shows the two moving bars on the left side of the screen, I cannot see the left bar at all... even if I crank brightness all the way up. Per the Avia instructions, I belive you should at least see the left bar a little bit.

    Now -- note that I have had two of the infamous Panny "evil pops" and did the service menu fix per the instructions on the panny.tv site. But the last one was like 6 months ago, and I didn't notice this black/white level problem then.

    I'm coming up on my one-year anniversary (and warranty) of the TV and am wondering if there is something really wrong.

    Any thoughts or ideas?

    Thanks in advance for any help...
     
  2. Jeff Pounds

    Jeff Pounds Second Unit

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    bump...

    Anyone have any ideas here?
     
  3. Michael Reuben

    Michael Reuben Studio Mogul

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    Bumping posts is frowned upon, Jeff. It's in the HTF rules.

    I don't have any experience with Panasonic sets, but you might want to try nudging up your contrast (assuming you're not past the point of blooming) and then rechecking the brightness. What you're describing could indicate that the light output is simply too low.

    M.
     
  4. Jeff Pounds

    Jeff Pounds Second Unit

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    D'oh! Double post...
     
  5. Jeff Pounds

    Jeff Pounds Second Unit

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    Michael,

    Sorry for the bump, but thanks for the advice.

    I did try and bump up the white level (picture), but it seemed that in order to get it high enough to where the black level was correct, there was a bit of blooming.

    Do you think that this could be a defect that might be covered in the warranty?

    I purchased it at Ultimate Electronics, and I'm wondering if they would accept Avia calibrations to prove that something is wrong...
     
  6. Michael Reuben

    Michael Reuben Studio Mogul

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  7. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    The TV will lose 30 to 40% of its light output over the course of the first 12 to 18 months. It just does ... and it is normal.

    After this drop off ... you need to essentially redo the whole set up to get back to that light output you started at.

    Reboost the contrast a bit and redo the brightness and other user parameters.

    Regards
     
  8. JohnnyG

    JohnnyG Screenwriter

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    If you've fiddled with the screen controls to fix your "pops" then it's possible that the G2 voltage is too low to generate proper output levels. The solution is not always to decrease one control, but to increase the other two.
     
  9. Jeff Pounds

    Jeff Pounds Second Unit

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  10. JohnnyG

    JohnnyG Screenwriter

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    Give it a shot, but the CUTs might not be enough in this case. You might have to adjust the screen controls. Have fun!
     

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