Sony Micro hi fi cmt-cp500md standby button

The standby button on my system refuses to allow me to turn the system on. Despite using the remote, manual buttons, auto play, etc. NOTHING gets the unit turned on. I haven't used it for a while due to other music systems , but I just tried to turn the thing on this evening to listen to some Joe Walsh, and it's dead. I really like this compact system, and I've had it 5 years. Please advise if you can. Diolch.