Unpredictable signals from my Xperia tablet

Hello everybody,
I am using an Xperia Z2 tablet with WiFi and from the last couple of days it started making some sound and showing double Vibrio sign even it is not used. Also, its alarm clock got turned off, WiFi not able to turn on. It looks like some problem with the tablet itself.
How can I make it work? Please advise me on how to resolve this issue. Thanks so much guys!
