Lightning Struck AKAI Active Surround System Restored
MAKE AND MODEL: AKAI ACTIVE SURROUND SYSTEM/ACTIVE SUB-WOOFER MODEL SS-803-W
COMPLAINT REPORTED: Dead
PRELIMINARY WORK DONE: Opened the set, steps: Remove four screws from the front panel, gently take out the panel, inserting a flat screw driver underneath without causing damage to the plastic part. Remove four screws of the grill at the rear that projects out (bottom portion and not the top one, which is the woofer). Gently take it out. Remove the screws that hold the metal plate on to the cabinet. Gently insert a flat screw driver to detach it from the cabinet. Both the front and rear might have got stuck hard with the cabinet. So we need to pry these out.
Cleaned the set thoroughly using blower. Dismantled the front and back portions. Cut the black wire that is ground for the transformer outer shield, leaving a portion on the PCB for joining it later during re-assembly. The connectors to be removed are (1) AC input to the Transformer – 2pin located at AC input PCB (2) Transformer AC output to Main Board – 3 Pin (3) Two pin connector with white wires located at AC input PCB, that go to front panel for the Mains on-off switch (4) Two black wires that go to main volume control pot in front panel – 2 pin (5) Two pin connector – Red and black – that goes to Woofer (6) 11 Pin connector that goes to front panel. Slid out the cables that go to the front panel through a hole provided in the inner frame. Once again cleaned all the boards and hard to reach portions thoroughly.
VISUAL INSPECTION: Fuse was found blown. Looked for any bulgy or leaked capacitors, burst parts etc. As the soldering sides of the PCBs were having left over flux that had got hardened and become dark, used a metal brush and cleaned all these neatly. Noticed a track cut in the ground of LED power indicator, in the front panel board. This track was next to the AC input, and lightning could only be the source which would have cut the track due to high voltage arcing. There were a lot of dry solder joints to such an extent that the tips got loosened when I cleaned the board.
TROUBLESHOOTING AND RECTIFICATION DONE: Checked for any shorts of semiconductors using Analogue Multimeter, keeping it in X1 Range, as advised by Jestine Yong in his book ‘Testing Electronic Components.’ (https://www.testingelectroniccomponents.com/) Did not find any short or leak in the output transistors and diodes. The ESR of the caps showed way out of range. Replaced all the electrolytic capacitors on the main board and the front panel board, which had the pre-amp ICS in it. Looked for any other track cuts. Retouched all the solder joints on both the boards. Joined the cut track by a wire. Cleaned the boards thoroughly using IPA. Allowed the board to get dried up fully. Lubricated the connectors using switch cleaning oil. Cleaned the Main volume, bass, treble and Rear speaker volume controls and lubricated. Covered the 230V AC tracks on the front panel with a few layers of plastic tapes to avoid accidental touching by hand (preventing a possibility of articles coming from me cut off permanently! (LOL)) Connected the boards, Mains Transformer and Woofer, speakers, audio input and applied power. Slowly increased the mains volume and got the output. The system was working very well without any distortion even at full volume. The controls also turned smoothly without causing any noise. After ensuring that the set worked well for a long time, switched off power, dismantled the boards and refit it back into its cabinet, joining the ground wire back to the TX, duly putting a sleeve to avoid its touching any other hot spots. Once again tried it for several hours before calling the customer (who happened to be my school classmate) to come and pick it up. Luckily, this set not only survived a lightning attack, but also lived up to undergo a total rework! Job satisfaction, of-course, was more than happy to jump itself to join the comrades!
HERE ARE A FEW PICTURES: (The purposeful comments are to provide some humor!)
This article was prepared for you by Parasuraman Subramanian from India. He is 70 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.
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You may check on his previous repair article below:
https://jestineyong.com/burnt-and-badly-leaked-capacitor-found-in-samsung-crt-tv/
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11 Comments
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Albert van Bemmelen
September 19, 2020 at 7:11 pm
Thanks for your repair report on fixing this Akai surround system, dear Parasuraman. I wondered however reading the text what numbered actions you were mentioning without showing any matching drawing or photos?
Parasuraman S
September 19, 2020 at 10:27 pm
That's the sequence to be followed for any new technician who wants to open and troubleshoot a similar model and make. We can know that only when the set is in front of us. No corresponding images were provided due to limitations.
Many thanks!
Henrique J. G. Ulbrich
September 19, 2020 at 9:41 pm
That´s a very good idea to put humor in the maintenance report. The result is superb. Thanks for sharing this interesting article. Glad to know you continue alive, even with AC voltage exposed.....
Parasuraman S
September 20, 2020 at 8:55 am
Humor will form in our mind automatically, when we enjoy every bit of our work. Many thanks for your encouraging comments.
John hsuing
September 19, 2020 at 11:16 pm
Ss 803 I want this modile kit board so pls parcal this board .... Is my addres
496A Rabindra sarine kolkata 700005
Parasuraman S
September 20, 2020 at 8:56 am
Sorry, dear! I do not deal in such boards!
Waleed Rishmawi
September 20, 2020 at 8:05 pm
That is a lot of work and a lot of capacitors to replace. It must have taken a lot of time and fun as well. Keep up the good work. I enjoyed the comments associated with the photos.
Parasuraman S
September 22, 2020 at 3:30 pm
Many thanks, dear friend!
Yogesh Panchal
September 22, 2020 at 3:40 pm
Some manufacturers are using Fuses Just for show.
fuses are always get blown after allowing severe Damage on the PCB.
Punch lines in Photos making article more interesting keep-up Sharing.
Parasuraman S
September 24, 2020 at 11:53 pm
Many thanks! Yes, fuses many times do not protect the circuit, but is 'selfish' to protect itself! (LOL)
Riz Khanna
November 17, 2021 at 1:47 am
i have exactly same akai home theater. sounds good...
but one problem is there that the bass speaker circuit is not working fine..
i tested the speaker from other source... it is working fine...
but onboard cirucit of bass is faulty... it sounds very crack...
other speaker and tweeters are working fine....
can you suggest... what is the problem....