331-2KV Cap Blasted

 

 

 

 

This LG 32″ LED TV came in for repair with the complaint of no power. From experience, no power usually are due to failure in power supply and the main board. Eventhough power supply is working, if the mainboard is not working, it will cause symptom like no power. So the first thing you need to check is to make sure the main fuse is not blown and that the power supply must produce good dc supply voltages. In the below photo, the power supply and the mainboard was not covered but the T-con board you can see it was covered with a metal shielding. 

The main fuse did not blow and I have to use visual inspection to see if there is any burnt component.

Seeing the circuit board from one side is not good enough to judge if there is any burnt component. You have to look at the board from different angle.

True enough, looking at another angle I found the 331-2kv capacitor was blasted. Since I found a bad component, I had to check on all the corresponding components too. Remember, you do not need to be a professional TV repairer in order to check the electronic components. Just go through Jestine Yong’s ebook in Basic Electronics Repair you can already start the electronics components checking and in fact you can use his methods to check on other electronics circuit boards.

Okay let’s continue, further checking found three components that were bad and need replacement. I’m taking the risk of not replacing the power IC but of course I have used a light bulb to test it first.

The light bulb went off with good DC output voltages indicating the power supply was good. I put everything back and powered On the TV and the display came back normal. See the photo below:

Conclusion- If after putting in the light bulb and if it bright or no DC output voltage, guess I have to replace the power IC and retest it again. Okay will see you again in the next repair article.

This article was prepared for you by Suranga Bandara who owns an Electronics repair shop in Anuradapura, Sri Lanka.

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Note: You may check out his previous post in the below links:

https://jestineyong.com/31-8-vdc-is-not-good-enough-to-power-up-led-tv-backlight/

 

11 Comments

1. 

   Yogesh Panchal

   April 6, 2020 at 4:35 pm

   well done! suranga.

   Likes(1)Dislikes(0)

   Reply
2. 

   Parasuraman S

   April 6, 2020 at 5:02 pm

   A good and useful article. Many thanks for sharing!

   Likes(1)Dislikes(0)

   Reply
3. 

   Albert van Bemmelen

   April 6, 2020 at 10:08 pm

   Pro repair. But like in previous repair you did not specify all defect components by name and/or type. Since the photo is sadly not clear enough to see the marking on the defect but important semiconductor you had to replace to get the TV working. And neither did you mention what LG type it exactly was.

   Likes(4)Dislikes(0)

   Reply
4. 

   Mark

   April 6, 2020 at 10:35 pm

   You are a Guru in these things. Step by step explanations, very educative for us the disciples. Keep it up and stay safe

   Likes(3)Dislikes(1)

   Reply
5. 

   Andrew F. Ali

   April 7, 2020 at 12:07 am

   Good job.

   Likes(1)Dislikes(0)

   Reply
6. 

   Waleed Rishmawi

   April 7, 2020 at 5:39 pm

   thanks for sharing your experience with us. LG sets are very well known of these faults. it would give your repair article extra value if you can share the damaged part number information. keep up the good work and have a blessed day

   Likes(4)Dislikes(0)

   Reply
7. 

   DOĞAN

   April 7, 2020 at 8:17 pm

   Greetings from Turkey.
   A very good article.

   Likes(2)Dislikes(0)

   Reply
8. 

   k . mohan

   April 8, 2020 at 11:29 am

   hello sir
   nice job , your good trouble shooting,
   your sharing, very thanks,
   your sharing my life very usefull thanks lord.

   Likes(3)Dislikes(0)

   Reply
9. 

   Uduak Essien

   April 11, 2020 at 3:37 am

   Good work from u guys. Thank u for your good works. Pls in this publication, I need you to clear my curiosity about the power IC being lighted with good dc supply indicating a good power IC and in the contrary a bright bulb with no dc voltage supply indicating bad power ic- and how does the power IC looks like here, pls I need to see its image. Pls note that I am interested in buying your eBooks but presently not too financially buoyant for now because I believe do much in your books. As soon as I can I will purchase the materials. Thank you, God bless you. Uduak from Lagos state in Nigeria.

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   Reply
10. 

    Humberto

    April 15, 2020 at 10:09 am

    Well done, Suranga. As usual.

    Likes(0)Dislikes(0)

    Reply
11. 

    Subhash.p

    April 19, 2020 at 8:42 pm

    Good article. ...

    Likes(0)Dislikes(0)

    Reply

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