Pincushion Problem In CRT TV Repaired

 

 

 

 

 

 

 

 

 

Customer sent in this Singer CRT TV with the complaint of pincushion out. This means that the display at the right and left side will curve inward as seen from the top and bottom photos.

 

There are usually few common causes to this problem such as:

1. Low B+ voltage to the Flyback transformer
2. Shorted modulation diode
3. Shorted pincushion transistor
4. Open resistor at surrounding area of pincushion transistor
5. No control signal to the base of pincushion transistor

However, in my case is pretty straight forward because I saw a bulged e-cap (1000uf 35 volt) at the horizontal output area-see the photo below:

Upon further inspection, I found a dry joint in the diode’s leg that is located at corresponding circuit. When i checked the diode with my multimeter I found that the diode was shorted. Checking it off board also produced the same result.

I did checked on other components as well that is related to the pincushion circuit but all seems to be good. So, just by replacing only the two components brought the TV back to life again .

If you want to be good in CRT TV repair you can check out Humphrey’s ebook in CRT TV repair. See you again in the next article.

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

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P.S-  If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!

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

https://jestineyong.com/how-to-repair-no-sound-problem-in-sansui-hi-fi/

 

13 Comments

1. 

   Parasuraman S

   July 3, 2017 at 10:55 am

   Excellent! Expertise in action!

   Likes(7)Dislikes(0)

   Reply
2. 

   Yogesh Panchal

   July 3, 2017 at 4:05 pm

   Good job!Suranga.

   Likes(4)Dislikes(0)

   Reply
3. 

   Tariq

   July 3, 2017 at 4:39 pm

   Thank you. But I'd need further information about the pincushin transistor like location and job.

   Tariq

   Yemen

   Likes(6)Dislikes(1)

   Reply
4. 

   Mark

   July 3, 2017 at 7:43 pm

   Well done Suranga!

   Likes(3)Dislikes(0)

   Reply
5. 

   ANGELO

   July 3, 2017 at 11:30 pm

   THANK YOU SIR "SURANGA"
   COULD U OR ANYONE PLZZZ PROVIDE ME SOME PICS OF PINCUSHION AREA?
   THANKS IN ADVANCE...

   Likes(4)Dislikes(0)

   Reply
6. 

   Jai Etwaroo

   July 4, 2017 at 4:35 am

   Good job Suranga

   Likes(1)Dislikes(0)

   Reply
7. 

   Albert

   July 4, 2017 at 12:17 pm

   As soon as I read 'pincushion' I knew it had to do something with e-caps. Good pro job Suranga.

   Likes(3)Dislikes(1)

   Reply
8. 

   Humberto

   July 4, 2017 at 12:33 pm

   Excellent Suranga.

   Likes(2)Dislikes(0)

   Reply
9. 

   Robert Calk

   July 6, 2017 at 11:48 pm

   Good job, Suranga.

   Likes(0)Dislikes(0)

   Reply
10. 

    mahmoud_tajpour

    July 9, 2017 at 5:01 am

    Thanks Suranga best job well done.

    Likes(0)Dislikes(0)

    Reply
11. 

    parashu ram singh

    July 11, 2017 at 1:16 pm

    nice video and got knowledge from given fault and sir
    you are providing me outstanding information and good too.
    thanks for cooperation in future.

    Likes(0)Dislikes(0)

    Reply
12. 

    Calum

    September 4, 2017 at 9:57 am

    good job bro

    Likes(0)Dislikes(0)

    Reply
13. 

    Mason

    February 27, 2019 at 8:36 am

    Make a service mode blog

    Likes(0)Dislikes(1)

    Reply

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