I've got no signal

[eldc67]

My signal has gone altogether

I've taken out the sim

I've switched on and off

I've restarted the network settings

I've manually selected O2

My data is on 

I don't know what to do and no store is near me! 

Please help

[pgn]

Tips given out here if you are not travelling, @eldc67 - Guide: Is the network down for me or everyone? 

And here: Guide: How can I sort out my network issues? 

Just in case it is something obvious, to start?