Dear Forum:
I am having an audio problem with a Sony STR-AV240 AM/FM Stereo Receiver. With volume on moderately low-mid output, the sound coming from the speakers and the binaural aspect of my headphones will occassionally stop. But I can still get monaural from my headphones. In order to fix the problem, I have to increase the volume. Sometime, just a small amount, sometimes 3/4 of max. The problem is totally intermitten as is the temporary fix. I have tried to clean the volume control with a tuner cleaner and that helps only marginally. Now I'm beginning to think it could be a transformer problem since I only have enough power to drive one side of the headphone and no speakers. But, this seems to self correct when I crank-up the output. Your help is greatly appreciated. Thanks! Mac
Sony STR-AV240 Receiver
Sun, 08/21/2005 - 09:20
#1
Sony STR-AV240 Receiver
My guess... A short in somewhere in the headphone jack, or in the cord leading up to the headphones. Maybe even a problem with the connection inside the headphone jack.
When you're playing with the volume, you probably move in a way that makes an intermittent connection.
Thanks for the comment Matt. Perhaps I was a bit vague in my original message, but the problem is not only in the headphones, but the external speakers also. I can fix both the speakers and headphones temporarily by jiggling the volume control but if it's the volume control, why do I still get mono on the headphones.
I must have read over the part about the speakers. That does change things a bit doesn't it?
I would have a hard time believing the problem is the transformer given the behavior, but with elecronics... anything is possible. I'd say that if spraying the volume control helped the problem (even a little), then that is most likely the culprit. You could try replacing the volume control entirely.
If you can't find a replacement part, you can add external volume controls for the speakers and headphones. This way, you can leave the volume control in a position that works without blowing your ears off.
Thanks Matt. Great suggestion. I'll give it a try.
You also can check solder joints in the outputs,
You also can check solder joints in the outputs,
This is an old problem but I'm willing to bet that the problem is with the output protection relay. These get a bit corroded a bit and require a higher volume (or voltage) to bridge the gap. If it is the type of relay that can be opened, burninshing the contacts will fix the problem. Otherwise replace the relay.
The other cause of similar symptoms is a bad connection within the headphone jack. Many receivers pass the output signal through the switching capability of the headphone jack. Bad connections here will result in one or more sides not working. Spraying the jack and repeatedly inserting headphones will clear this up.
Great call Dan as have seen this a dozon or so times myself. Also in a case like this, the center rotor sweep on the volume control can develop corrosion or even a mold like sunstance and cause an intermittant volume control variable. Hopes this puts this to bed.
Thanks folks. I appreciate the suggestions.