Here are some options that can be done to resolve your issue
• Restore the original factory settings.
- Select Menu > Settings > Restore factory sett.
• Update your device software.
- Updating the software may improve your device performance and solve software issues like the one you experience on your phone.
If your issue remains unsolved, contact Nokia for repair options. Go to www.nokia.com/repair. Before sending your device for repair, always back up the data in your device.