Some of us might have face this problem before on N73. I have this problem myself few months ago. When i receive sms, there was no ringtone from my N73(i didn't set silent mode) . I don't know when is the msg received, but it is inside my inbox. It is kinda annoying as i miss many sms and need to keep checking my inbox cause my N73 wont ring.
After a few try on my phone, i found the problem and solution. The problem is there are too much sms in the inbox. I had more than thousand sms insides my inbox and i never bother to delete it. So to solve it:
- Delete the old sms on your phone as much as possible.
- Restart your phone.
This should solve the problem, it work for me. Hope it help.