Not sure of the Sony, but some other phones go into 911 mode if 911 is dialed - then every call goes only to 911. Somewhere in the settings there should be a Mode selection - normal, airplane, emergency, etc.
Hi Anonymous, If you've locked your phone through entering an incorrect pin number 3 times then you need a Puk code, Ring your service provider and they will give you the FREE Puk code.....
If you lock your phone again sometime in the future and you're still with the same service provider you can use that same Puk code.. BUT if you've forgotten your pattern code The link below is a YouTube video of a guy showing 3 ways but the 3rd way is a factory reset meaning you loose everything in your phonebut the first two ways are worth watching. Also there's videos down the right side that may help..... I hope this helps...... CHEERS..
https://www.youtube.com/watch?v=dmBqvh1UUD4EASY WAYS How To Unlock Android Passwords
There are three possibilities to get this type of issue.
1.There may be a problem in your Sim card so try another one.
2.Your mobile is locked to particular network provider.
If your problem persists,After replacing new Sim card means definitely Your mobile phone is restricted by some network so try to unlock your mobile phone.For unlocking you can approach your service provider or else try to buy an unlocking service from any one of the online unlocking service provider like Unlock-Zone.com Here you can unlock your phone at low cost.