Galaxy Ace problem

[Anonymous]

Hi, I have had my galaxy ace for nearly a year now.. and up until today had no problems. However when trying to check my balance I get the usual "ussd code running" message but then it changes to "Connection error or invalid mmi code". I have taken the battery out and reset the phone several times and it works like normal for a while but then the same thing happens again. I notice this when it doesn't allow me to send any messages via text or What's ap.. What I'm wondering is if anyone can explain why this is happening. The phone has not been rooted or flashed. 

Any help would be greatly appreciated. 

[MI5]

Check first for any known signal issues or planned maintenance in your area http://status.o2.co.uk/

[Anonymous]

Hi, thanks for the tip. Just checked it says the network is running fine in my area and there are no scheduled maintenance or unforseen issues. 

[MI5 · Accepted solution]

I can't honestly think of any other reason unless the phone or SIM has developed a fault. If it plays up in different locations and you start to get lots of network errors it may be worth swapping for a new SIM to see if it helps.

[Anonymous]

Ok thanks for the info ill give it a try.... 

[MI5]

Good luck and let us know how it progresses.....