Sound I've only had my tv for four years, recently the sound started fading in and out. Now the voices sound really hollow and any music associated with a show only comes through in interrupted short fragments. Is this fixable or should I go out and purchase a new tv?

Some TV's have sound settings to empathies voice. If the TV has a centre speaker you can increase the sound output on that. That will make voices louder.
However many people do complain about loud music drowning out voices on TV. The problem is that movies were meant to be seen in cinemas and TV sound systems don't match up to that. If you can't find a solution consider a surround sound system as this will correct the sound problems on movies.

the capacitors on the power unit has to be replaced or new power unit .

This type of sound can be generated by the back-light inverter board.

The audio portion of the main board is failing. You can get a replacement here: TV Parts Universal TV Stands DLP Chips ShopJimmy

Turn the VIP level all the way down for the microphones you are using over the Mp3 music. If the VIP levels are up, the music will fade out so you can make an announcement.

I had this problem with my previous TV (Syntax by Olevia, an off brand). It only happened to me on certain channels, and for certain shows. What is happening is the TV station is broadcasting the audio in Dolby 5.1 format. For some stupid reason, the TV is playing the background speakers (effects) instead of the speaking parts. You get a little bleed-over of the voices into the back speakers, so voices are there but really quiet. Unfortunately my TV didn't have any surround sound options to fix this.

See if your TV has a surround sound option. Otherwise, you will need to connect the TV sound output to a surround sound system that can properly decode the audio channels.

If you locate the audio board, check for dried up electrolytic capacitors and dry joints around the output IC itself.
That should fix your fault.

Try changing the needle and if that don't work check for any type of loose wiring

How does it sound using external speakers? What is your signal source...broadcast, cable, satellite? Is the static continuous or does it fade in and out with voices (lips moving) and / or sound effects / music?

i think the Tv is Normal working. No need to replace the TV. the problem only in your audio processing circuits. Audio driving unit or Audio power amplifier IC might be faulty. You can replace this IC and get the real sound back. To do that contact authorised service personnel. all the best