Happy New Year Broken Down Audio Amplifier Restored Back to Life
This amplifier was brought to me by a pastor with complaint the amplifier got burnt in the new year day 12am midnight immediately after members of his church shouted happy new year. What a coincidence!!!. It’s a two channels sleeve amplifier.
As usual I removed the case cover, clean inside, also clean the two fans inside (one fan for each channel) and with visual observation, I could see some burnt resistors on one channel’s board.
I suspected there may be some passive bad components which visual check will not detect, so I use my meters to check all components on this board.
With this I found transistor 2sa1943-shorted( PNP, collector shorted to emitter),C5198- open, A1931-open,the big white resistors are open and some other defective components.
The second channel board is intact. So I replaced all bad components with good ones.
Then I powered amplifier and it came alive, call the Pastor, who came, took it to his church for testing and called to confirm audio is loud and clear. See pictures below:
This is the finished repaired work.
This article was prepared for you by Imoudu Onwumah from Nigeria. He is 62 years old and has just 3 years experience in electronics repairs. I started career in hotel industry as a chef, but then I was doing repairs only in electrical repairs as a hobbyist. In 2018, I decided to learn about electronics which through Jestine’s electronics e-books and holding my hand, am an electronics techie today.
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Note: You can read his previous article on Bruhm LED TV Repaired
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pv beveren
March 18, 2022 at 10:47 am
It's a good feeling to restore an item to serviceability using skills learned...good job
Tayo
March 18, 2022 at 1:56 pm
You deserve a medal for going above and beyond the call of duty. Very well done!
Albert van Bemmelen
March 18, 2022 at 2:22 pm
Quite a coincidence indeed, or the at midnight shouting voices into the (stereo) mike must have caused it?
Parasuraman S
March 18, 2022 at 2:50 pm
Amazing co-incidences and a fix! So professional and looked so easy though we all know how complicated the problem was! Well done!
Babu M S
March 18, 2022 at 10:45 pm
Very good repair work.Nicely identified the defective components and I am excepting many more articles
Imoudu Onwumah
March 19, 2022 at 6:13 am
Mr Parasuraman
Thanks for your comments.have a nice day
Tito Kanshulu
March 19, 2022 at 7:24 pm
Very good repair Sir. Keep the fire burning.
Imoudu Onwumah
March 19, 2022 at 6:16 am
Mr Albert
Perhaps the shout, "shorts" the transistors.have a nice day friend.
Waleed Rishmawi
March 19, 2022 at 4:26 pm
indeed what a coincidence !!!!!. that is a big damage I wonder what was the cause of all that? thanks for sharing your repair and have a blessed day
Yogesh Panchal
March 19, 2022 at 8:37 pm
Good repair! with lots of patience and off course you are lucky to have
working intact second channel board so that you can find exact resistor value else this repair was difficult to tackle
Carlos Bielli
March 21, 2022 at 5:23 pm
I think it is a good idea to add an air filter at the air input of the unit.
Franklin Aniemeke
April 5, 2023 at 2:24 pm
Good day sir. How were you able to know the value of the resistors that got burnt