LG CRT TV with picture problem repaired. Model: RT-29FA34RB

By on October 5, 2013

 

 

 

 

 

A very unusual problem with this CRT TV was brought to my shop by a friend of mine. I powered up the TV set and here is what I saw.

 tv repair

From experience, I thought it was a vertical problem caused either by bad vertical IC or few bad capacitors. It turned out to be a repair adventure and new experience. Let us begin.

I took a few screws off and the inside of the TV was exposed to me.

 tv repair

My thinking was focused on the vertical IC and the surrounding capacitors. I took the ESR meter out and found four bad capacitors. I found two 2200uf/25 volts and two 47uf/25 volts.  I powered up the TV set and that did not solve the problem. I measured the voltage reading at the vertical IC and I got 13 volts coming all the way from the fly back transformer at the high tension area. The vertical IC with part number LA 7841 was getting the right voltage and because of that, I thought that this IC was bad. I changed it but it did not solve the problem either.

 tv repair

My thinking shifted to another cause of this problem. I know for sure it is a bad capacitors problem because when I blew hot air on some capacitors on board the problem disappeared and when I used cold air, the problem started again.

I have found a board that is soldered to the main board of the TV set. It has lots of small tiny capacitors and seems like most of these capacitor were bad. I thought to myself, if I change the whole board that would be a lot easier than replacing all these capacitors. I looked around in my storage room and I was lucky to find exactly the same board. Before, I soldered back on board, I checked all the capacitor with ESR meter and I had to replace two of them.  They were 100uf/25 volts.

 tv repair

It was not easy to take it out because I have lots of soldering joint to de-solder. It was still easier than replacing all these capacitors on that board. Once I replaced the board, this was the result.

 tv repairing

It took me about two days to find the cause of this problem. Everybody was happy. Mission accomplished.

waleed

 

 

 

This article was prepared for you by Waleed Rishmawi, one of our ‘Master Authors’ and currently working in the Bethlehem area of Palestine repairing electrical and electronic equipment. Please give a support by clicking  on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.

By the way if you have any good repair article that you want me to publish in this blog please do contact me HERE.

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58 Comments

  1. mustabz

    October 5, 2013 at 11:25 pm

    This is a very important article especially it involves a working set that needs fine tuning.
    However u didn't tell us what that board does and how come some sets don't have it
    Congratulations keep it up.

    Likes(1)Dislikes(1)
    • Waleed Rishmawi

      October 7, 2013 at 6:35 pm

      thanks Mustabz. the baord is audio and video card. so many capictor that needed to be replaced but since i have a used working board in my shop, it was eaiser for me to just replace the whole board. link:http://www.go-gddq.com/upload/2010-02/10020811494321.pdf
      this is the ling that ZED shared with us in my comment section. thanks ZED.

      Likes(2)Dislikes(1)
  2. Bernie Scott

    October 6, 2013 at 12:02 am

    Good article......I see that you don't give up.....I have to get into that mindset more often....I have so much stuff to repair that when I run into a difficult time consuming problem I have no choice but to lay it aside and barrel through the tons of equipment I have to repair....I have not done consumer equipment in a very long time...I mostly repair music related equipment such as guitar amplifiers, keyboards, electronic pianos, reel to reels, etc.....vacuum tube, solid state and the latest technologies.....I get much enjoyment from these articles and sometimes they give me the insight to keep pushing along and every repair job is something different and new. I am constantly learning.....,thanks to articles like these from Jenstine and other people like yourself.....Keep up the great work. It is much appreciated......

    Likes(1)Dislikes(1)
    • Waleed Rishmawi

      October 7, 2013 at 6:36 pm

      giving up is not in my dictionary. you are welcome Bernie

      Likes(0)Dislikes(0)
      • Marshall

        December 16, 2016 at 3:34 pm

        Thank you for this read, my question is what voltages are required at other pins of the verticle ic to judge if its dead? I seem to have the same problem.

        Likes(1)Dislikes(0)
  3. jshields

    October 6, 2013 at 1:11 am

    Both articles are interesting and well written,
    thanks sharing them with all of us.
    Jim

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:37 pm

      you are welcome Jshields

      Likes(1)Dislikes(0)
  4. raymundo saura

    October 6, 2013 at 9:23 am

    thanks for this article it is my pleasure of recieving this kind of article, helpful on my part especially on repairs thanks and GOD bless

    Likes(2)Dislikes(0)
    • Jestine Yong

      October 6, 2013 at 4:35 pm

      HI Raymundo,

      You are welcome!

      Jestine

      Likes(2)Dislikes(0)
  5. Naseem

    October 6, 2013 at 1:16 pm

    Hi Dear Walid,
    thank you very much for the nice article... could you show us what board and capacitors you replaced... and what was the function of that board.
    regards,

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:39 pm

      it is a video audio board. ZED was so kind to share the schematic with us. here is the link. link:http://www.go-gddq.com/upload/2010-02/10020811494321.pdf
      enjoy

      Likes(1)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:41 pm

      there were too many capcitors to be replaced but sincei i have a used working board in my shop, I just replaced the whole board. it is a video audio card.
      http://www.go-gddq.com/upload/2010-02/10020811494321.pdf

      Likes(1)Dislikes(1)
  6. andile

    October 6, 2013 at 1:31 pm

    Great articles thanks they rily opened my mind widely

    Likes(0)Dislikes(1)
    • Waleed Rishmawi

      October 7, 2013 at 6:41 pm

      you are welcome Andile.

      Likes(0)Dislikes(0)
  7. Joshua Oloo

    October 6, 2013 at 1:39 pm

    Thanks alot for the two Articles they're educative and they give hints on how i can repair the gadgets.I've one guestion,How can i fix a TV with colour patches on the screen?the images has several colour on screen

    Likes(0)Dislikes(1)
    • Waleed Rishmawi

      October 7, 2013 at 6:43 pm

      Joshua
      check the degusing circuit in the baord and make sure the PTC part is in good working order. it that did not help, it might be a crt panel problem. check it out and let me know if you need more help.

      Likes(0)Dislikes(0)
  8. Timothy Gitari

    October 6, 2013 at 2:10 pm

    That is very interesting in both articles.I have realized that in the second article, that my TV had that small problem than i thought.Thanks very much now i can watch my TV once again.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:44 pm

      Timothy, you are welcome. I am glad you have liked the artilce.

      Likes(0)Dislikes(0)
  9. Tyrone.

    October 6, 2013 at 6:25 pm

    Thank you again for this interesting article.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:45 pm

      Tyrone, you are welcome

      Likes(0)Dislikes(1)
  10. PRUDENCIO G. PERITOS JR.

    October 6, 2013 at 6:25 pm

    I'm very glad to recieved this kind of articles especially LG CRT TV.as i have observed you did it...And i hope it will add more knowledge to me in repairing TV set.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:46 pm

      Prudencio: I am glad you like the article. keep up the good work

      Likes(0)Dislikes(0)
  11. Romulo

    October 6, 2013 at 8:18 pm

    Thanks for this precious information. Though I'm not in this kind of repair at this time but it will be a great help to me in the near future. By then I hope I can also share some of my repair experience. Thanks again.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:46 pm

      you are welcome Ramulo. God bless you

      Likes(0)Dislikes(0)
  12. Tana

    October 6, 2013 at 9:56 pm

    When I saw the title , I told myself this must be a good read.It did turn out to be a goog read, because I have gone through this type of problem many a times, for almost 40 years, I am now 67 years old. I have slowed down. I hope you keep on posting these repair articles for the benefits of the young beginners.I must say your presentation was well thought out and laid out in the photos .
    Thank you Waleed.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:48 pm

      Thanks Tana
      thanks for the ecouragement and I will do my best to keep writing these articles. God bless you in a mighty way

      Likes(0)Dislikes(0)
  13. Percy Ichchaporia

    October 6, 2013 at 10:47 pm

    Dear Waleed and Jestine thank you for sharing this information. I really find it interesting to read your blogs and all monthly articles.Please keep up the good work of updating us as and when you can.

    Thanks again,

    Best wishes,
    Percy

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:49 pm

      Percy: you are welcome. glad you are enjoying the articles. God bless you

      Likes(0)Dislikes(0)
  14. Zed

    October 7, 2013 at 9:27 am

    Thanks for sharing waleed for this repair. I think the circuit that is faulty is the audio video card that is pinpointed in the picture. here is the schematic diagram link:http://www.go-gddq.com/upload/2010-02/10020811494321.pdf

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 6:33 pm

      yes it was. thanks for sharing. it was fun to work on this tv set.

      Likes(0)Dislikes(0)
  15. petr

    October 7, 2013 at 1:46 pm

    Thank's a lot!

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 8:52 pm

      you are welcome petr

      Likes(0)Dislikes(0)
  16. reza

    October 7, 2013 at 4:52 pm

    hello mr yong & mr waleed
    i use at this article
    thank u very much

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 7, 2013 at 8:52 pm

      you are welcome Reza

      Likes(0)Dislikes(0)
  17. Humberto

    October 7, 2013 at 6:57 pm

    A good article. God bless you

    Likes(0)Dislikes(0)
  18. Waleed Rishmawi

    October 7, 2013 at 8:53 pm

    Humberto: thank you and your are welcome. God bless you too

    Likes(0)Dislikes(0)
  19. Mark Tembo

    October 7, 2013 at 11:10 pm

    Thanks Waleed for the article. I have noticed that you do a lot of these repair jobs and also share with us. That is very good of you. Please, keep it up becuase people like me do benefit a lot.
    Thanks!

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 8, 2013 at 3:48 pm

      Mark: I am glad you are benefiting from these articles. thanks for the encouragement to keep going. have a good day. by the way, Mark is a wonderful name. that is the name of the my son as well, he is almost 3 years old. God bless you

      Likes(0)Dislikes(1)
  20. Andre Gopee

    October 7, 2013 at 11:52 pm

    Great article, I like reading these type of article for Mr. Jestine, You and all the other. Thanks Jestine for this site and repair articles. God Bless.

    Likes(0)Dislikes(0)
    • Jestine Yong

      October 8, 2013 at 9:57 am

      Hi Andre,

      You are welcome!

      Jestine

      Likes(3)Dislikes(0)
  21. zed

    October 8, 2013 at 9:46 am

    Thanks waleed. May we share continue our repair experienced to help others too.
    Zed

    Likes(1)Dislikes(0)
    • Waleed Rishmawi

      October 8, 2013 at 3:50 pm

      that is the idea Zed to help others because a lot of people helped me a long the way, for example Mr Jestine and others and try to bless other just like these people blessed me. have a good day my friend

      Likes(0)Dislikes(0)
  22. glen

    October 8, 2013 at 8:35 pm

    Nice repair tips.thanks for sharing.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 9, 2013 at 4:24 pm

      Glen. you are welcome.

      Likes(0)Dislikes(0)
  23. Remy Francis

    October 8, 2013 at 9:09 pm

    Thank Waleed
    Very good article and also thank for the hot air tip.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 9, 2013 at 4:23 pm

      you are welcome Remy. glad you enjoyed it

      Likes(0)Dislikes(0)
  24. solo

    October 9, 2013 at 6:01 am

    This is good

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 9, 2013 at 4:22 pm

      Solo. thanks

      Likes(0)Dislikes(0)
  25. bluemango

    October 9, 2013 at 11:56 am

    thank you Sir Justine and Sir Waleed for sharing this article. More power and God Bless.

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 9, 2013 at 4:22 pm

      bluemango: you are welcome. God bless you too

      Likes(0)Dislikes(0)
  26. Dave

    October 9, 2013 at 8:14 pm

    As you did not find the actual bad component on the old board, it could also be a poor solder joint. In my experience with CRT monitors I have found that the hot/cold test will temporarily fix this problem as well. It is usually found near a heat generating component.
    Dave

    Likes(0)Dislikes(0)
    • Waleed Rishmawi

      October 10, 2013 at 4:31 pm

      dave: not really, at least not in this case.I took it out and before I put the replacement, I checked it out for bad soldering joint and found none. that is what I did. I found a lot of bad cappacitors on that board but I thought replacing them would take time but since i have a ready board just replace it and get it over with. it is a mater of saving time.

      Likes(1)Dislikes(0)
  27. Jayaprakash

    October 22, 2013 at 5:38 pm

    Thank u sir, its very interesting

    Likes(0)Dislikes(0)
  28. bongsky

    February 9, 2014 at 7:58 pm

    thanks for another information about this article, another repair tips that will help us in trouble shooting good day.

    Likes(0)Dislikes(0)
  29. ravindra madisa

    January 13, 2016 at 11:47 pm

    hi I have a lg CRT TV.but now it was giving only output by audio but not by visual

    Likes(0)Dislikes(0)
  30. nirankar

    October 20, 2016 at 8:13 pm

    sir
    lg 14" ultra slim TV but no audio singnal

    Likes(0)Dislikes(0)
  31. Jetsdi

    May 25, 2018 at 4:47 pm

    Thanks mr waleed.... Any idea for distorted picture problem for crt tv?

    Likes(0)Dislikes(0)
  32. Pushpa Raj

    June 13, 2018 at 9:12 pm

    I have LG CRT TV, when I power ON few minutes running normally, after few minutes the picture is increase darkness after that the screen will darty. But the audio come. Please reply
    Thank-you

    Likes(0)Dislikes(0)

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