At one point is it a hardware failure? I've inspected all profiles to ensure settings correct. I pull the battery and the ringer work0s for incoming calls for maybe an hour, then no longer rings. When the ringer is dysfunctional, the speaker phone still works but the alarm does not sound. Seems so much like a setting considering speakerphone still works. I tried a hard reset last week and same thing -- worked for an hour (or less) then stopped working. Of course I'm about 2 weeks past my one year warranty.

Just an update...after I had done the hard reset a few days ago, I then updated my BB software and reloaded most of my personal stuff from backup. Something in this process is messing up the ringer. Tried another hard reset yesterday and haven't updated the onboard software nor restored any of my previous stuff. Ringer is working. I'll be slowly reloading stuff, seeing if I can determine what's breaking what.

Sprint store was no help. Wanted $120 to "fix" it, and gave zero advice.

I had this behavior with one or two firmware releases. I finally just wiped the device and loaded 4.5.0.89 which I'm pleased to say works flawlessly. You might consider the same.

Search on here for JL Commander and use it to delete the current firmware. That's the only way to downgrade / load a lower version than the one you have. You will need to take backups of your apps and data, but it sounds like you're familiar with that.

Consider optimizing the memory utilization while you're at it by not loading certain themes/app modules. Search again for that - there's an article.

Nowadays, I don't even bother to load newer firmwares until they've been out for quite a while. But, I'm still on 4.5.0.89 because it works.