O2 No Signal Network Down (Tesco Mobile / GiffGaff unable to call problems)

O2 Network Down with No Signal  (so also affecting Tesco Mobile and GiffGaff)

O2 users are continuing to have problems making calls and sending texts across the UK. It isn't geographical as the people I know with no signal are in totally different parts of the UK from Manchester to Kent & Sussex.

If you are having problems please leave a comment to help show what areas are affected across the UK and how many people are affected by this problem with O2 which also covers Tesco Mobile and GiffGaff phones which use the O2 network.

UPDATE - 0845 on Thursday 12th July 2012 


O2 have stated that the problem is "affecting thousands". Based on the number of people I know on O2 that are still unable to make calls this is a gross underestimate of the numbers affected. I would guess it is in the millions not thousands.
The problems are still continuing today and from Manchester to London to Eastbourne & Dover O2 mobiles are still unable to make calls. Some are showing full signal but still not able to make calls or send texts. Others have no signal at all. O2 have stated the problem is due to a failure in their core network but it has also now caused their website to crash so users are unable to check status updates.
.
One suggestion to resolve the problem has been to turn off data roaming if you have a smartphone like the iPhone but this may not work with all affected phones. Someone else has suggested that one factor may be whether phones have an original O2 number or were migrated from other networks but this may not be a common factor.

UPDATE - 11pm on Weds 11th July 2012 
O2 have issued a statement that the problems are due to a failure in their core network. Friend's mobiles are still showing no signal nearly 12 hours after it started.

O2 Network Down (Again) with No Signal

This problem also is affecting Tesco Mobile and Giffgaff networks which piggyback on the O2 transmitters so are impacted by failure of any parts of the O2 mobile phone network. Amazingly considering the extent of the outage and disruption across the UK the Tesco Mobile website has no information at all about the problems and the O2 website has crashed under the volume of hits.

If you need to check the location of O2 transmitters in your area to see where the nearest is located then click here for more info