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Sony STR-6050 FM sound problem

I've had this tuner-amp since 1969 and has worked wonderfully. Today my FM sound instantly went from 'normal' volume to where I had to jack the volume up to max. Any ideas? Can it be fixed? Is it worth fixing? If not any suggestions as to a decent tuner-amp of equal to better quality? Thank you.



fatagnus's picture

Sony STR-6050 FM sound problem

You may also try cleaning the tuning capacitor itself - carefully. Spray or place a few drops of DeOxit on each of the three to four bearings that hold the shaft. Rotate well and do it again. Follow up with a quick burst of canned air.

Sony STR-6050 FM sound problem

when the FM signal volume drops, does it get a lot of static noise?

Sony STR-6050 FM sound problem

You may have a problem in the multiplex circuit, or in the power supply for that circuit.
Is audio OK in all other modes?

Sony STR-6050 FM sound problem

Yes.

Sony STR-6050 FM sound problem

Phonograph, CD player and AM radio have fine sound.
The FM signal can go from very low volume to suddenly get loud/'normal' (when I've turned up the volume to hear the low volume FM signal).

Sony STR-6050 FM sound problem

You might try cleaning the function switch (AM, FM, Aux).

Sony STR-6050 FM sound problem

How difficult is that? I down loaded a service manual but it seemed close to useless which would suggest that disassembly and cleaning must be a no brainer. Is cleaning really that simple?

Sony STR-6050 FM sound problem

You need to get a spray cleaner that is made for controls; I use Deoxit D5. Just spray a little on the switch contact areas, move the switch a few times, then let it sit for a while. If controls are a little noisy you can do the same for them.
Note: some controls and switches are difficult to get to; there may be boards or other components in the way. There are several types of controls; some easier to work with than others. Usually you can spray cleaner into them from the terminal side (they have 3 terminals); sometimes they have a small hole on the side or an indent in the metal body where cleaner can be sprayed.
Do not use too much; a little goes a long way.
This may or may not solve your tuner problem.