Techwood lcd tv 32722hd picture problem

Question

Tv works fine for 20 mins until the picture dies in a matrix like picture and then goes black finally but still displays sound. I have checked all cables they are fine so, the power supply i am using is the correct one too.

I have a video in motion if someone would like to help me out im just interested if it would be worth fixing and how much it would cost?

Emanuel

Answer 1

Have a continual humming sound whether volume is high or low.