How To Repair No Sound Problem in Sansui Hi-Fi
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.
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.
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.
The next test was to check on the DC supply to the digital controlled stereo audio processor TDA7318D.
Below is the link of the TDA7318D Audio Processor IC:
http://www.alldatasheet.com/datasheet-pdf/pdf/25125/STMICROELECTRONICS/TDA7318D.html?
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.
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.
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:
https://jestineyong.com/led-tv-no-sound-repaired/
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Parasuraman
June 26, 2017 at 5:20 pm
Expert solution to this otherwise complicated problem.
Ronald
June 26, 2017 at 8:45 pm
Thank you very much. Your articles are such a blessing to many
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!
Chetan
December 18, 2022 at 11:35 pm
Sir how did you open the system i mean the outer cover i got stuck at this.please would you like to help me in this regard. Iam also facing same sound problem.
Thanx in advance
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?)
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?
Victor
June 27, 2017 at 2:11 am
Good job suranga keep it that way cheers.
Gerald Musy
June 27, 2017 at 7:10 am
Well done Suranga. Thanks for sharing
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
Ulises Aguilar Pazzani
June 27, 2017 at 11:49 am
Mr Suranga grate fix , thks for sharing
ramli
June 27, 2017 at 2:31 pm
fantastic...tq for yr sharing.
Olusegun Fadare
June 27, 2017 at 4:02 pm
Thanks
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.
Georg
June 28, 2017 at 4:58 pm
I would like to know the functions of capacitors.
myatsoeaung
June 29, 2017 at 11:15 am
Thanks for sharing.This is the good job.
Robert Calk
June 29, 2017 at 9:45 pm
Good job, Suranga. Thanks for the article.
Richard
June 30, 2017 at 11:08 am
Good one
luke
June 30, 2017 at 11:25 pm
Smart job done
Humberto
July 1, 2017 at 1:26 pm
Good repair Suranga. Thanks for sharing these articles.
Phil
July 16, 2017 at 3:33 pm
That's great workmanship Suranga. Thanks for sharing.
janaka
January 6, 2021 at 8:15 pm
Dearsuranga my sansui mc-s 855 v hi fi setup demegs. You sansui hi fi setup Available ..?
chethan
December 8, 2022 at 1:06 pm
dear sir , i have a sansui micro component cd player/cassette deck/amplifier hi -fi system model no 1450 where i am not getting any sound . 96 model (year make). please help and guide me