Sony Audio amplifier takes long to "warm up"

Jul 13, 2005 5 Replies
R

I have a background in electronics but not in audio amplifier. I have a Sony Audio amplifier, a 25 years old model. I turn on the power and it takes 20 to 40 minutes to hear the music. Just before I hear the music, There is a ZZZZZZZZZZZZZ then a CLICK. Each selection (Tuner, Aux or Tape) works or does not. Once the amp works, it works until I turn it off.



On what stage, from the power supply to the audio output, I should look at? What type of component I should look for ( capacitor, relay, transistor)?



Do you have a suggestion of a web site?



The purpose of this posting is to understand how an audio amplifier works to repair it.



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M

Electrolytic capacitors, probably. I'd guess in the power supply, the audio output and the protection circuit.

Met vriendelijke groet, Maarten Bakker.
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L

Sounds like a weak cap on the relay drive circuit.

Leonard

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S

a good possibility.... or just as likely: cold, cracked or otherwise faulty solder connections on pcb near and around the high heat producing power resistors, semiconductors, etc.

-- Best Regards, Daniel Sofie Electronics Supply & Repair

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D

Sounds like the speakers are fed via a relay - commonly to prevent a thump in the speakers at power up time. There will be a timing circuit associated with it. May be even they trip out if there's a large DC offset through the amp.

*You can't teach an old mouse new clicks * Dave Plowman dave@davenoise.co.uk London SW To e-mail, change noise into sound.
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