Something has definitely gone wrong. When picture fails, generally the audio will still play; but since the set is shutting down completely after a short time - it is going to more involved.
Firstly, anything can be fixed. The questions to ask are: 1) At what point do you stop spending money to repair a device that is XX years old? 2) How much would a replacement / upgrade cost?
Given that your set is an older SD (standard definition) with an old analog NTSC legacy tuner, it may be worth while to make the move to a digital HDTV. The picture quality will "blow away" any SD version of the same image / program that your old TV displayed. Unlike several years ago, the HDTV has come way down in price, too. A 32 inch, wide screen HDTV price starts at just $235 as results shown by a search in Google
. In order to view HD signals, you'll need either 1) a plain UHF/VHF antenna (and local broadcasters in range), 2) HD cable TV service or, 3) HD satellite service. Cable and satellite providers offer SD service and for slightly more, HD service. Most people are not happy watching SD signals on an HD display - so you'll probably want to change the level of service if you're not using an antenna. Old DVD players only send SD signals, you might consider upgrading to a Blu-Ray player. Blu-Ray players provide SD and HD signals - depending on whether you insert an SD DVD or an HD Blu-Ray disk. The Blu-Ray players, like the HDTVs, have also dropped in price significantly.
See if you can find a place that provides free estimates. If not able to locate, find someone that will apply the cost of diagnostics (ask what the diagnostic fee is) to the total repair charge, and decide to either fix or replace.
I hope this helps and good luck! Please take a moment to rate my reply - thank you.