Question about Toshiba 55H70 55" Rear Projection Television

2 Answers

Green Pillow after Conv ICs replaced

I had the problem described here and elsewhere about the STK392-110s failing. I replaced them and fixed the power problem, but there is still a problem. It's best seen in service grid mode, the red and blue grids look good, but the green is distorted like a pillow. The vertical lines are all straight. The horizontals are curved away from the center line which is straight.

Any suggestions. I don't have a service manual yet.

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  • 7 more comments 
  • TomDunlap Dec 05, 2007

    Thanks for the reply. No, to be honest, I didn't check them. I don't have a schematic or a picture to locate them. I did see a reference to 180K feedback resisters and replacing the 1/8w with 1/4w. Any clues as to what they look like? I did notice three large green ones and 3 smaller ones but I didn't get the size of of them. They are mounted closest to the ICs.

  • TomDunlap Dec 06, 2007

    I realize that, but now I know how, I can replace them again. I just downloaded a service manual from www.service-manual.net and am printing out the pages I need of the schematic and PC board but I still don't know exactly which resistors to check. Here's a screen shot of one of the STK392s. Can you say which ones to check?

  • TomDunlap Dec 06, 2007

    I'll get it to you tomorrow, thanks.

  • TomDunlap Dec 09, 2007

    Did you get the schematic? was it readable?

  • TomDunlap Dec 10, 2007

    It should be there. Thanks again for your help.

  • TomDunlap Dec 10, 2007

    The jpeg I tried to send is 173k. Is that too big?

  • TomDunlap Dec 11, 2007

    Did you get the email without the attachment?
    I'll try zipping the file tonight.

  • TomDunlap Dec 11, 2007

    Zipping a the jpeg is only going to knock it down to about 130k.
    Another thought, my isp is Bledsoe.net but my mail gets readdressed as ToolkitMail.com Could that be a problem?

  • TomDunlap Dec 12, 2007

    I replaced the 3, 1.2 ohm 2W resistors, R7711, R7721 and R7716. One, R7721, was obviously burned and read .6 ohm. This straightened the Green grid and I was able to tweak all of them in, in the service menu. Good job, thanks again for your help.

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2 Answers

The zip is on it's way. I'll check the resistors tonight and let you know.

Posted on Dec 11, 2007

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  • Master
  • 4,402 Answers

Did you check the resisters? also there is a reset that youcan do on the remote, go to this site:
http://www.digitalhome.ca/forum/showpost.php?p=564268&postcount=220
http://cmpalmer.blogspot.com/2006/11/fixing-my-own-tv-part-ii.html

Posted on Dec 05, 2007

  • 7 more comments 
  • Cary Farah
    Cary Farah Dec 06, 2007

    you might have blown the new ic if any of the resisters are bad.
    look here:
    http://www.digitalhome.ca/forum/showpost...

  • Cary Farah
    Cary Farah Dec 06, 2007

    can you email me the pdf or jpeg i can see it clear enough to give you the number you will need.
    ctf1800@yahoo.com

  • Cary Farah
    Cary Farah Dec 10, 2007

    no i didnt please send again and put schematic for title.

  • Cary Farah
    Cary Farah Dec 10, 2007

    Still nothing

  • Cary Farah
    Cary Farah Dec 11, 2007

    im not getting anything so it must be do you know how to zip?

  • Cary Farah
    Cary Farah Dec 11, 2007

    Yahoo usually accepts anything, try sending the zip file

  • Cary Farah
    Cary Farah Dec 11, 2007

    I did see a reference to 180K feedback resisters and replacing the 1/8w
    with 1/4w. Any clues as to what they look like? I did notice three
    large green ones and 3 smaller ones but I didn't get the size of of
    them. They are mounted closest to the ICs.

    those do sound like the resisters
    unsolder one end and test them with a mutimeter.

  • Cary Farah
    Cary Farah Dec 11, 2007

    there will also be three by the output stage you will see a set of three plugs they have four colored wires going up to the tube, if you look on the board they are right next to these plugs again unsolder one side and test with mutimeter.

  • Cary Farah
    Cary Farah Dec 12, 2007

    hey Tom for some reason Guest got the points and i didnt can you recheck this
    thanks

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Here are some photos of convergence problems.

42d3683.jpg

7859b01.jpg

e87380c.jpg
Here is a quick test....

Using your original remote go-to the settings menu then goto the convergence section.

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69189a5.pngCONVERGENCE SOLUTION

You will need to replace the convergence chips and possibly some convergence resistors and pico fuses.
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http://home.earthlink.net/~oleg.filippov/ConvergenceFix.htm
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http://home.earthlink.net/~oleg.filippov/ConvergenceFix.htm
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