Mobile data connection problem in Nokia lumia 630 Double Sim

Hi Robert

Thank you for posting again.

The problem you're describing seems to be specific to your particular unit.

I wonder if you could switch the two sim cards places, would it make any difference.

Insert SIM1 into tray 2 and SIM2 into tray 1.

I would also like to ask you if the phone ever worked properly in connection with the sim cards in question.

Another thing you could try is to inroduce a 3rd sim card to see if the problem still occures and if not

The next step I would recommend, as a way of elimination of any software/apps related reason for the issue would be to backup your phone before proceeding with hard reset.

Here's information about backing up:

http://www.windowsphone.com/en-gb/how-to/wp8/settings-and-personalization/back-up-my-stuff

and here about performing hard reset:

http://www.windowsphone.com/en-US/how-to/wp8/settings-and-personalization/reset-my-phone

Please be aware of the fact that hard reset will clear all content of the phone that is not backed up.

If the problem's still there after hard reset I recommend to try replacing the problematic sim card with

new one with your mobile operator (ask them to issue duplicate).

In case that doing so, still doesn't solve the issue ,

It most likely going to be the case of replacing your phone.

Please let us know on the progress

Thank you

Marek St.