This only happens sometimes, indicating my phone is working, but it drives me crazy that I could not answer some calls, and I don't know how to prevent it
Hi again Grindale!
I am also having the same issue as above however I am unable to check for a software update. When I go into settings then about phone I do not have the "Software update" option. It is simply not there. I've checked all the other options and settings but I don't have it anywhere??? Help please :)
You can consider doing a factory reset on your phone. That sometimes work in resolving issues on phones but you need to make sure that you have already made a backup of all your phone's content such as messages, pictures, contacts, etc.
1. From the home screen press Menu and then tap Settings > Privacy.
2. Touch Factory data reset > Reset phone.
3. If necessary, enter your password and touch Erase everything.
The phone resets to the factory default settings automatically and when finished displays the Home screen.
Another option is upgrading your phone's software. Upgrades usually resolve bugs in previous software versions. To check if there's an upgrade available for your phone go to Settings > About phone > Software update.