Question about Audio & Video Receivers
I have a sony str db1080 Reciever amp its about 5 yrs old. It has started making a buzzing from teh speaker channels. I have tidied up all wires and have tried switcing off all potential interference sources like TV Sat box etc. but it makes no difference. The sound gets louder when the volume is increased. I have noticed that the longer the amp stays on the sound diminishes.
Can anyone help?
First, let's distinguish a buzz from a hum. A hum is a clean, 60 cycle signal that sound like a tone. A buzz is 60 cycle noise created when the power filtering circuit is not doing it's job. This is basically a 60 cycle hum, but because of the way the faulty filter reacts, it "distorts" the signal slighly and is a buzz. Trust me on this if you don't want a full electronic explanation. If you are curious and would like one, email me seperately.
If it is a buzz, chances it is the filter capacitors, but lets not jump to that conclusion yet, this can only be fixed by a professional, so let's try the free fixes first!
You might have 1) a ground loop, 2) faulty house AC. What is the age of your house? Are you using any three prong to two prong adapter? If so get ride of them.
But the first obvious thing is to look inside the unit and see how dusty it is. UNPLUG FROM WALL before opening. Use a can of compressed air if necessary. Now try. Dust build-up causes static electricity with can play havoc with electronic componenets, but normally not 60Hz, but it's worth a try.
Before I get into the ground loop, do you have any flouescent lights in the area? These use transformers which tend to put a 60Hz buzz through wiring it is directly attached to, but only when on.
Check if this buzz is consistant with any selected device (DVD, CD, Radio, etc.). If it is true of all, continue on, if of one, disconnect that particular device and see if it stops. Just turning off a device still keeps it in the elctrical loop...
A ground loop can be caused by a broken wire. It is important that every compnent be grounded to a single point. With a broken wire this can cause multiple paths to ground. disconnect everything, all components from the receiver, antennas, any cable running to another component, etc Just leave the main speakers hooked to the receiver and turn it on. Hopefully you have "audio snow" but no buzz. This method is called isolating the problem. If the buzz disappears skip to the 2nd paragraph. If you still have a buzz: unplug unit from wall, try a 3-2adapter into the wall. If this works, you have a faulty ground. Bring receiver into another room and try. Same result with buzz? (with or without 3-2). Go to a hardware store and purchase a ground fault indicator and make sure your house wiring is OK. Very inexpensive part. You simply plug it in a the lights tell the story. Usually two yellow lights and one red. Both yellow on indicate everything is fine.
Up until this point I am taking it for granted tht the power cord from the receiveris three pronged. If it is NOT, try running a thin wire from the outlet (attach using the center screw that hold the outlet cover in place) to a screw on the receiver. It would not hurt to try this even if it is a three pronged connector in case there is a broken ground within the unit.
Hook up and test each component until you hit the one the causes the buzz. When this happens, try using a different cable as this one is probably broken. If it doesn't stop, try what we tried for the receiver, if it is a three prong electrical plug, use a 3-2 adapter, still buzzing, now try adding the extra thin wire between the two compnents.If it a two prong, add the ground wire from the component to the receiver.
If all else fails it needs to go into the shop. But I will say this. Compare the cost of getting an estimate/repair with purchasing a new unit. It might actually be less...
Hope this helps,
Posted on Jan 14, 2008
Bad filter caps. Have them changed out and see if that helps..accordianman
Posted on Jan 14, 2008
Sounds like a capacitor is taking a long time to do it's job. You might want to see how much it would cost to repair.
Posted on Jan 14, 2008
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