LG 32LE4900 has image but no sound at all

I've had my LG 32LE4900 quite a few years now and its a great TV. Picture is crystal clear and still rivals more expensive sets these days in my opinion.

Quite a while back the sound completely went. I was just watching TV quietly and suddenly everything gradually got more distorted then there was a bang. Now the internal speakers don't work and neither do the audio outputs. Also, when trying to change volume it seems very laggy whereas it was fast and smooth before.