Exact same thing happened to me. I am in the process of shipping it out for repair. The unit is of terrible construction and the electronics flaked. I actually got a sub -woofer and wireless surround speakers for my TV which are 10 times better.
I had similar trouble. Was about to return and them it suddenly turned on. Have no idea but it has been a year since and working fine. Touch wood. My suggestion - unplug and try after a while. Nothing scientific.