N1 shutting off on its own

Hi, my N1 sound bar is shutting down by itself after 2-3 minutes. It used to work well, then when I was turning it on via the remote, it was not working and even if I tried the hard button. I had to unplug it and plug it back in order to make it work. Now it is getting even worst as after unplugging and plugging back, after 2-3 minutes it shuts down...any help?