I had bought a LG Convention model in 2011. The usage of this is not so much in our house and mainly for heating food items.
All of a sudden the Start button stopped working while all the other buttons were working. We called up LG toll free and they come and checked the machine. They said that they do not have the display card hence the only option left with us to submit our bill and get money back after deducting the depreciation.
It seems to be such a small issue but they cant repair and we have to give up the entire machine. Also to note is that inspite of not having much use, the machine has stopped working in just 2 years.