Is the outlet you are using getting power? Is it a gfi? Check the breakers to see if they have tripped. Some of those home theaters have serious wattage and can trip breakers. if all of that fails, then the system is no good. Sorry.
Google rooting cell phones. There's a software program you have to download to the phone and then follow the instructions exactly. Beware: this could make your phone inoperable if you don't do it right.