Sim card detection problem

[Addyj]

Hi,

     Sir I'm having a problem with my Xperia U, whenever i'm turning on my airplane mode my phone works properly, but when i turn off my airplane mode and start using normal mode then my phone screen suddenly dis-appears, and the light situated on the lower most part of the phone is continuously on, which means my phone is on but it do not show the screen.
 What should i do? Please help me, do i upgrade my software versio from gingerbread to ice cream sandwich or this is a hardware problem?
 Reply as soon as possible. Waiting for your reply.
 Thankyou.
 Regards,

                  Adnan ahmed.

[Johan]

You set the topic to SIM card detection problem.

Is it so that when you disable flight mode the phone is not able to detect the SIM card?

In that case I suggest that you try using another SIM. Maybe this could be the reason the phone is acting up as well.

If changing the SIM card can't cure the problem with the phone acting strange you can try running the phone in safe mode to check if this may be caused by any downloaded application.

http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008