maybe check ur sim slot or try ur sim to other phone if is no signal ur problems its in sim if not at same try to hard format ur n8
If you're unfortunate enough to encounter a problem on your Nokia N8, a hard reset maybe what you need to do. This wipes the entire phone memory and settings fresh to how it was (or should be) when you bought it. It's also useful if you're also unfortunate enough to have to send away your Nokia N8 for repair or exchange, or maybe in future you maybe selling it and don't want your information/details/media stored onto your device for someone else to access.
Hopefully unlike the N97, the N8 will not encounter hard-reset bugs where we constantly have to hard reset.
To hard reset the Nokia N8:
1) Turn off your phone
2) Hold "Volume Down + Camera Key + Menu Key" and press power button until your phone vibrates.
3) Wait until screen show properly... and welcome back!!
or try this one
How to Master Reset Nokia N8 do the Factory Default Setting?
If our Nokia N8 have problem such as hang or not responding or slow or stuck or have problem or frozen, then what we can do is try to restart the phone first to erase all temporary file and clean the cache. If the Nokia N8 problem still there then the last thing we can try is to do Master Reset to Factory Default Nokia N8 with safety way.
#Option 1, Hard Reset Nokia N8 with Menu Setting:
If we still can access the menu, then do this step:
- Go to Setting Menu
- Choose Phone
- Choose Phone Management
- Choose Factory Setting, after that choose Delete Data and Restore
- The Nokia N8 will reset all data for factory default, please remember before doing this step for always backup any important data before it deleted.
#Option 2, Hard Reset Nokia N8 with Hardware Key Button:
If we can not access the menu with screen, or the LCD is not responding, we have to hard reset Nokia N8 with secret button key:
- Make sure you understand that all data will be deleted, so do backup as you can
- Turn off the Nokia N8
- Press the Hardware key together: Volume Down Button + Camera Button + Menu Button
- Still continue the no.3 step (do not release), continue with pressing Power Buttonwait until the phone vibrate to start the factory reset Nokia N8 automatically.
#Option 3, Hard Reset Nokia N8 with Secret Code and Phone Lock Code:
If we want to format Nokia N8 with security code, try this :
- Make sure you already backup all important data before do the factory reset
- From the Phone Positions, type : *#7370#, after that press YES
- It will ask the Phone Lock Code, if you never change it, the default Phone Code of Nokia N8 is 12345
- What about if we forget the Phone Lock Code of Nokia N8: We suggest to bring the Nokia N8 to nearest Nokia service center.
