Servicing AKAI Active Surrond Speaker System Model SS803S

By on May 13, 2017
replace capacitors

 

 

 

 

 

 

 

 

 

 

 

 

akai surround sound repair

This system was brought to me with the complaint that it is dead and lying unused for a prolonged time. As usual, I opened up the set and subjected it to thorough cleaning and dismantled the boards one by one. The grill at the rear first, then the amplifier board with its heat zinc, which also has the power  in board with fuse, input/output connections.




Then removed the front panel. Kindly have a view of the main board and also the inside of the box, where the transformer is fixed.

   akai surround speaker repair

fix akai surround speaker

On observation, I noticed that one of the 4700mfd/35V cap is burst and its ESR reading is .24 instead of .05 and the 4A Fuses at the secondary AC input are blown (Fuse at primary was ok):

  repair akai speaker surround

how to fix akai active surround speaker

Just have a look at the dried flux on the boards (Input/output board, AC in board with Fuse)! The main board was also as bad as this, but forgot to click it!

       how to fix akai active surround speaker system

how to repair akai active surround speaker system

how to repair akai active surround speaker

Cleaned all the boards thoroughly using IPA and metal brush, repeating the process until the board was as clean as this: PCB BOARD

As the boards had a lot of dry solder and the ESR readings of many of the Electrolytic Capacitors were out of range, I replaced all the capacitors on the board, which is my exciting amusement whenever I get a chance to do it! I replaced 41 Electrolytic Capacitors on the boards! Once again cleaned the boards and inter connected the boards keeping it outside. The set worked perfectly well!  So, assembled the system back to its original shape (You can see that the LED is lit):

 how to repair and fix akai active speaker system

Here are the components that I replaced: replace capacitor

Another satisfying service accomplished!

This article was prepared for you by Parasuraman Subramanian from India. He is 66 years old and has more than 30 years’ experience in handling antiques equipment Valve Radio, Amps, Reel Tape Recorders and currently studying latest techs classes conduct by Kerala State Electronics Technicians’ Association. He was a BBA graduate, retired as MD of a USA company.




 

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You may check on his previous repair article below:

http://jestineyong.com/servicing-laptop-adapter-key-model-7150/

 

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17 Comments

  1. Albert van Bemmelen

    May 13, 2017 at 5:52 pm

    Another timeconsuming repair you did Parasuraman Subramanian. Seeing all e-caps you had to replace like in previous repairs, it is almost a wonder that there was found no apparant reason why they all were bad. 41 bad e-caps must be your personal record? I wonder if the device still would have worked after replacing only the worst bad e-caps? (if maybe the device was manufactured with the same bad quality e-caps from the start and also did work with those all that time?).
    Sorry to see you still had no chance to replace your old bad low resolution camera Parasuraman?

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    • Parasuraman S

      May 13, 2017 at 10:28 pm

      I think the record was greater than this; almost around 100! All caps were definitely not bad. But I resort to this method in order to give the set new life in toto!

      Camera: I got a new mobile phone and am yet to master the high class camera in that! Sorry, kindly bear with me!

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      • Albert van Bemmelen

        May 14, 2017 at 6:21 am

        No problem Parasuraman. I understand, but I almost never use my smartphone myself to make photos with it. I even removed both SIM phone cards from it because it phoned when I didn't want to, and did hangup on calls unexpectedly too. I think any device without real buttons is trouble ! And like you say those devices need learning time to master were they should be working intuitively.

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  2. Robert Calk

    May 13, 2017 at 6:48 pm

    Good job, Parasuraman.

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  3. Henry

    May 14, 2017 at 9:41 am

    Impressive job with all 41 e-caps replaced. It is certainly a new lease of life for the old and previously neglected Surround Sound System.
    I wonder how you actually decide on whether the ESR value is correct or unacceptable. You mentioned that "the 4700mfd/35V cap is burst and its ESR reading is .24 instead of .05". The Blue EST Meter has a graph chart that only indicates some approximated ESR values, not very exact.
    So, can I ask where is the .05 value coming from?
    I recall a discussion on this forum some time ago about the ESR values and they generic and not necessarily precisely defined values. Google search delivers many examples of different tables showing some expected ESR values depending on the capacitance and the rated voltage of a capacitor. Just try "capacitor esr chart" and see them. They are claiming not exactly the same values either.
    So, that is why the .05 mentioned in the above article as correct but .24 as too high puzzles me.
    Apart from that I like the article.

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    • Parasuraman

      May 16, 2017 at 12:04 pm

      I check capacitance after removing whenever I find a suspected ESR value. I replace the capacitors only when both are out in most of the cases! Thanks for bringing this up!

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  4. Gerald Musy

    May 14, 2017 at 10:45 am

    Another fantastic job Parasuraman. Replacing all those caps makes sense as old e-caps will fail sooner or later.
    Thanks for sharing.
    Cheers,
    GM

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  5. Angelo

    May 14, 2017 at 11:58 am

    Nice to see two experts chit-chatting with each-other
    lol...
    When two experts meet such things happen...

    Good job sir
    parshuraman
    i jus love india n indians..
    Thank you

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  6. Mathew Charles Karonga

    May 14, 2017 at 8:38 pm

    Was expecting to Learn something from the questions asked by My Henry but I didn't see any responses not only from Parasuraman but also from anyone who can have answers in this forum hopefully some senior experts will give me answers. Well done on yet another impressive way of doing this job Mr Parasuraman

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    • Gerald Musy

      May 15, 2017 at 10:50 am

      OK OK Mathew I will try to answer. Henry is correct that the graphs on the ESR meter are not very accurate. Mine gives 0.1 for anything greater than 500 uF. But, also correct Henry, there are tables. This one for example:

      http://4.bp.blogspot.com/-nfR_85jZ93o/TrZdKYxxZ9I/AAAAAAAAAL0/mWmmVRZe8ZQ/s1600/esr+table.png

      gives 0.02 for a 4700 uF 35V. So 0.24 is definitely out, whichever the table you look at. Even-though various tables give you different values.
      A good trick is to measure a good cap and compare with the suspect one...

      And yes, replacing all the e-caps in this type of analog equipment is good preventive maintenance. Some might just be a little bit out of specs and might affect the sound quality, until they fail completely.

      Cheers,
      GM

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    • Robert Calk

      May 15, 2017 at 11:48 pm

      The Blue ESR Meter has a pretty good scale on it.

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    • Parasuraman

      May 16, 2017 at 12:11 pm

      I am down with a low back pain which happened like lightning when I tried to pick up a screw driver bending normally. Hence could not see the remarks on time to respond. I follow a chart which Justine Yong sent me when I bought the ESR meter from him. That is fairly accurate and I always compare the reading with the new one. I carry inventory of almost all components with me, including semiconductors.

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  7. Tito Kanshulu

    May 15, 2017 at 1:21 am

    Job well done sir. The numerous capacitors whose esr have gone to the roof . thanks

    Likes(1)Dislikes(0)
  8. Yogesh Panchal

    May 16, 2017 at 9:54 pm

    Good job! Sir.
    Just amazing!! what could be reason for this many capacitor failure.

    Likes(1)Dislikes(0)
    • Parasuraman

      May 19, 2017 at 1:17 pm

      The shelf life of electrolitic capacitors broadly 6 months only! When any set is lying unused, the electrolitic capacitor, which should be charged and discharged regularly, is the one that gets affected. Most of the electronic sets become defective because of neglect!

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  9. Tyrone

    May 17, 2017 at 7:00 pm

    Very good Parasuraman thank you.

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  10. Humberto

    June 3, 2017 at 8:42 pm

    Good repair Parasuraman, as usual. You are a Master

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