I have a Mitsubishi TV LT-55164 and used it for years then the front speakers went bad and I moved the TV to another room and used it with the audio signal through the RCA jacks to a surround sound system and worked for about a year then it started sounding bad once again and now I have no sound --- checked all settings and all were set to produce sound but nothing and the price of a main board is less than 100 bucks -- do you guys think the main board could be it