Tampered Amplifier Set Repaired
This Amplifier model Sonodyne SC1020 was brought to me by a regular customer with the complaint that it had on/off relay problems and it was given to a local technician, who could not solve it. Luckily, when a customer tells you openly that it was given elsewhere, we, technicians are always forewarned and look for unscrupulous tampering first. There indeed was such work on the PCB. The following pictures are self-explanatory not only for that, but also for very bad dry solders and a burnt resistor:
On checking the transistor, BC158B, legs of which were left unsoldered, the Peak Atlas showed:
Replaced this transistor and also the resistor, and did a retouch of all the solder joints on the board and cleaned it thoroughly.
Look at the inside of the Amp and the finished PCB.
Switched and the relay clicked after a few seconds delay, indicating that all was well in the Amp. Connected my USB player and checked the audio output. It was perfect!
For connecting the speaker outputs to EP type, I had made adapters, which I used in this Amp, as it was using Philips type.
I have made multiple connectors for various uses in the workshop, pictures of which, I shall share in one of my articles in the future.
So, the curtain fell on this service and got added to the satisfaction list, behind the screen!
This article was prepared for you by Parasuraman Subramanian from India. He is 69 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: