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Sony DAV-SR2 Rising High pitch oscillation noise on power up.

Lostfollicles

Jul 14, 2019
2
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Jul 14, 2019
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2
I have a Sony DAV-SR2 Home Entertainment system that has served me well for over 20 plus years but it has suddenly developed an annoyingly high pitched oscillation noise on start up but eventually rises to above "I guess" hearing range.
After 20 plus years I'm guessing it's a bad electrolytic capacitor problem on one of the outputs on the SMPS power supply, however
when the DVD player is chosen and in use there is no noise but all the other inputs when chosen i.e. >VIDEO/TV/SAT/AM/FM< emit this high pitch noise, so I assume the problem is on the supply side of the Audio decoder chips, am I wrong?
I would have attached a pdf of the service manual and sound file of the high pitch noise but this site does not allow it.
Thank you in advance for any help, it will be very much appreciated
Regards Lostfollicles
 

kellys_eye

Jun 25, 2010
6,514
Joined
Jun 25, 2010
Messages
6,514
Your diagnosis seems to be quite accurate. The high pitch is superimposed on the power supply rails to all sections of the amplifier so it would be down to those sections individual (local) filtering that decides whether or not it passes through.

Time to look more closely at the components.....
 
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