How To Repair No Sound Problem in Sansui Hi-Fi

By on June 26, 2017
how to repair sansui hi fi no sound

 

 

 

 

 

 

 

 

 

 

SANSUI HI FI NO SOUND REPAIR

Customer sent to me this Sansui Hi-Fi with the complaint of no sound even though the volume control already set to maximum.  The first thing I did was to connect an external speaker (see photo below) to the audio output at the back of the hi-fi to check if there is any sound coming out from the output jack.




There was no sound at all and I need to open up the cover and check for any bad components in the audio output circuit.

how to fix no sound in hi fi

Once the cover was opened I straight went to see the mainboard audio section to see if there is any broken tracks, loosen connectors, bulged electrolytic capacitors and etc.

sansui hi fi mainb board

They were all good thus I had to perform the DC supply test to the two main amplifier ICs. See the photo of the two arrows were pointing to the two main amplifier output ICs. The DC supply found to be good.

sansui main amplifier repair

The next test was to check on the DC supply to the digital controlled stereo audio processor TDA7318D.

sansui hi fi problem

Below is the link of the TDA7318D Audio Processor IC:

http://www.alldatasheet.com/datasheet-pdf/pdf/25125/STMICROELECTRONICS/TDA7318D.html?

tda7318d datasheet

tda7318d ic datasheet

The DC supply test was checked to be good. If you read the IC description it says that the IC has volume control, tone (base and treble) balance (left/right) and fader (front/rear) processor for quality audio applications in car radio and Hi-Fi systems. This means this IC controls lots of function that is related to audio. Since the DC supply was tested good, I directly replaced the IC with a new one and retested it.

tda7318d ic

tda7318d amp ic datasheet

I was right by simply replacing with a new IC , the sound came back to life again. Again I can use oscilloscope to check for the audio output signal but replacing the audio processor IC directly is much faster.

how to fix sansui hi fi no sound

suranga

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 previous post about fixing active speaker in the below link:

http://jestineyong.com/led-tv-no-sound-repaired/

 

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19 Comments

  1. Parasuraman

    June 26, 2017 at 5:20 pm

    Expert solution to this otherwise complicated problem.

    Likes(3)Dislikes(0)
  2. Ronald

    June 26, 2017 at 8:45 pm

    Thank you very much. Your articles are such a blessing to many

    Likes(0)Dislikes(0)
  3. Henrique Jorge Guimarães Ulbrich

    June 26, 2017 at 9:41 pm

    Dear Suranga, I find it very impressive the fast way you solve problems. Congratulations!

    Likes(0)Dislikes(0)
  4. Albert

    June 26, 2017 at 10:04 pm

    Perfect done job Suranga! I agree that soldering a new audio controller IC is much faster than checking all signals with an oscilloscope.
    Only the delivery time of about 21 days or more is always a hassle. Especially if you have a lot of customer devices waiting for parts to replace in your store. And having all sort of ICs in stock is of course way too expensive. Sadly the only electronic store in our town thinks exactly the same. (and they probably order in China too?)

    Likes(4)Dislikes(0)
  5. sylvester ongaya

    June 27, 2017 at 12:53 am

    Hi Suranga . Am impressed with the stereo repair article. Tis learning experience for me. I love to learn from you guys of Asia. I became an electronics repairman through reading RC Vijay, an Indian author.I still fondly keep Vijay's transistor radio troubleshooting, solid state tv troubleshooting and ctv troubleshooting. Currently am a part time repairer and hope to become full-time once I gather enough knowledge in modern electronics. Am Kenyan and mad about electronics repair. Any positive advice from you Suranga?

    Likes(2)Dislikes(0)
  6. Victor

    June 27, 2017 at 2:11 am

    Good job suranga keep it that way cheers.

    Likes(0)Dislikes(0)
  7. Gerald Musy

    June 27, 2017 at 7:10 am

    Well done Suranga. Thanks for sharing

    Likes(2)Dislikes(0)
  8. nitn vetal

    June 27, 2017 at 11:19 am

    Nice article sharna it's knowledgeable for my type of electronic hobier person and all of us thanks for sharing with us

    Likes(0)Dislikes(0)
  9. Ulises Aguilar Pazzani

    June 27, 2017 at 11:49 am

    Mr Suranga grate fix , thks for sharing

    Likes(3)Dislikes(0)
  10. ramli

    June 27, 2017 at 2:31 pm

    fantastic...tq for yr sharing.

    Likes(0)Dislikes(1)
  11. Olusegun Fadare

    June 27, 2017 at 4:02 pm

    Thanks

    Likes(1)Dislikes(0)
  12. mahmoud_tajpour

    June 28, 2017 at 4:44 am

    Hi dear Suranga thanks a lot this is the best repair by you and it was very useful for me.

    Likes(0)Dislikes(0)
  13. Georg

    June 28, 2017 at 4:58 pm

    I would like to know the functions of capacitors.

    Likes(0)Dislikes(0)
  14. myatsoeaung

    June 29, 2017 at 11:15 am

    Thanks for sharing.This is the good job.

    Likes(0)Dislikes(0)
  15. Robert Calk

    June 29, 2017 at 9:45 pm

    Good job, Suranga. Thanks for the article.

    Likes(0)Dislikes(0)
  16. Richard

    June 30, 2017 at 11:08 am

    Good one

    Likes(0)Dislikes(0)
  17. luke

    June 30, 2017 at 11:25 pm

    Smart job done

    Likes(0)Dislikes(0)
  18. Humberto

    July 1, 2017 at 1:26 pm

    Good repair Suranga. Thanks for sharing these articles.

    Likes(0)Dislikes(0)
  19. Phil

    July 16, 2017 at 3:33 pm

    That's great workmanship Suranga. Thanks for sharing.

    Likes(0)Dislikes(0)

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