LOUD BUZZING NOISE WHEN WATCHING TV, WHEN I MUTE TV IT STOPS

You have problems on the sound portion of your board. It could be a bad solder joint causing it to arc to another component or to ground. It could also be just a plain ole bad Amplifier or something. When you mute it you turn all the voltage off to your AF Amps and naurally the noise will stop. Find the sound board and check it for cold solder joints.
Gillight

Its audio output IC has damaged. Replace it.

Yes, all the issues point to a problem in the standby power supply which runs 7/24 if the set is plugged into wall power--get it taken care of under warranty before it really fails bad.

A common cause are failure of decopling capacitors in the audio section, and or the circuit board power distribution that feeds the audio board. Most of the capacitors are surface mount components. The standard fix is to start by changing the circuit boards that have the defective parts.

If the set is under warranty, call for warranty service. Out of warranty service is expensive for these TV sets.

Jerry G.

The main cause off buzzing from these sets is the transformers on the psu. This can be solved by sealing the transformers with a sealant spray.

It sound like you may have sound processor problem which is part of the main board, I would also look at the 12vdc from power supply to make sure it is clean DC.
Parts: http://www.shopjimmy.com/catalogsearch/result/?q=l37hdtv10a

http://en.wikipedia.org/wiki/Capacitor_plague

my 46'' inch tv polaroid lcd has been working fine for 3 years. today my wife and I noticed the tv is shutting off the screen will go black and the power light does switch to red. you can here something inside the t.v clicking but you can turn it on and it will start back fine for 20 minutes then shut off again? Does anybody know whats going out on the tv? let me know

Vizio makes an ok LCD, but if you notice they no longer make plasma. they stopped last year. Anyways. the buzzing sound is semi serious, it sounds as though you have a capacitor leaking. It is best to get it fixed before it goes out all the way, with it buzzing it will be easier to identify. Best of luck

It could be the inverter board going bad. The inverter board is what makes the back lights come on and has transformers on it that have high voltage. any time you have a noise like a buzzing or arcing you should have it checked

You maybe be able to turn the internal speakers off through the tv's menu...either in the Audio section or in Settings