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OT Bobby, I had asked you last week in regards to a JVC Television LT-42X788 with a with faint blue vertical bands screen, hearing sound and backlight working. You said that the problem would be the analog board and or the cable connecting to the digital board. Can you give me instuctions how to repair these faults and where to purchase the parts. I am in Toronto Canada. I have experience with soldering and using multimeters and know about electronic parts. How would I check the power cable and identify the parts that would need replacing? I can email photos of the exposed cards if helpful. I could not find a specific repair manual and the closest I have found online is for the LT-42X688 which looks quite similar but may have some differnt parts. Pleasze let me know if you can assist me with this problem. Thank you for your prompt reply, Willy Halpert

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  • whalpert May 26, 2009

    If there is no fix then where can I purchase at a reasonable price a new digital board and the flat connecting cable? Thank you for your prompt answer.

  • whalpert May 26, 2009

    If there is no fix then where can I purchase at a reasonable price a new digital board and the flat connecting cable? Thank you for your prompt answer.
    Had signed wrong user name. whalpert

  • whalpert May 28, 2009

    Thank you Bobby. It seems to be the analog board and/or the flat silver wires going to the digital board. I will try to purchase the board and the cable and a better soldering iron to give that a try first. I wish I cvould somehow compensate you for your great assistance and clearly described actions to be taken.

    My email is





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Soldering the Connectors will not fix this problem.
1. Remove the TV Rear cover.
2. Look at the wires on connected to the top of the middle board (Analog Board)
3. if they are White, this is 98% likely to be the cause of your problem. If the are a Tan/Khaki color these are OK.
4. If Tan/Khaki connectors on that middle board, I would replace the Video Process Board on the far right. Check Option 1 below for where to find boards.

I have a few options for repair of the white connector situation:

Buy the board on Ebay making sure you dont get one with the white connectors. You can use a board from the 42" and 47 inch versions of this TV. X688, X788, XM78 and I think they had a few others. Also, call JVC they may sell it to you. If not companies like Vance Baldwin or Aarons may sell it to you. This may be 40-140 depending on where you get it. The part number is on the sticker label printed on the board....not the generic label silkscreened onto the board.


Middle Board, Top Right connector. Remove the wires from the connector on the middle boards side and solder them directly to the board without the connector. This will not be as easy as it sounds. If done incorrectly, the problem will continue. If done correctly you will fix it. Also, take a look at the ICs at the top toward the connector and the similar ones along the board. Double check these to make sure they dont have any OBVIOUS damage. By Obvious I mean completly blown up or holes in them. Based on your symptom I am 98% sure it is the white connector thing but you never know.

I hope this helps and good luck. Also, unless you have a GREAT soldering Iron I don't necessarily recommend 2. These PWB have a large ground that transfers heat well. You can burn it if using the wrong IRON or TIP. 600Fahrenheit max for Lead free Solder no more :).

Posted on May 27, 2009


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@Thomas Scissons
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Please pick one:

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