Speakers in TV making a buzzing noise.

SOURCE: Polaroid FLM-323B HDTV Loud Buzzing

or you can cut off the end of some old headphones and plug it into the side headphone jack.  works for me.

SOURCE: Picture is blank when tv is turned on when cold.

There are likely to be many poor connections in the power supply section that are causing this. If you can solder and the unit is no longer under warranty, you can try resoldering any connections that appear grainy or have rings. That may resolve the problem. If not, than one or more capacitors have changed value enough for the internal circuits to mal-function. This will take some test equipment to locate easily. Try resoldering first and update this with the results. I'll try to locate the most likely parts that could cause this.

Dan

SOURCE: Buzzing sound coming from TV Speakers and any external speakers

change your pre-amp ic sure it will work. or maybe cold solder from the board.

SOURCE: Humming noise through Tv speakers. Goes away if I

If the noise is coming in through the onboard tuner then repair may the only option. If you have a DVD or VCR and can connect the line level inputs (look like stereo connections) then do so and use that input, if the sound persists there then it is likely the audio circuitry - also a repair item.
Bypassing the TV sound system involves connecting your cable box, DVD or VCR (using the tuner from that unit select channels) audio output to a stereo system and then the TV becomes a big monitor (picture only)

SOURCE: audio makes a siren noise, speakers pop and sound

no signal from my pc