I am on my second iPhone 4 - the first one was replaced less than 7 days after I got it for the same reason. The first time, it appeared to be due to a ringtone that was created by an app but all the repairs a tech walked me through over the phone did not work and she created a ticket and I went to the local apple store where they also could not fix it and handed me a new phone. The tech manager there said then that he thought it might be a Sprint problem. My sister has an iPhone 4 from a different service provider and the same thing happened to her. Since I got the new iPhone 4 in mid-June I've only had one ringtone - a purchased one from iTunes. A few days ago, the phone stopped ringing when I receive calls and playing alerts when I get texts or reminders pop up. It just does a weak vibrate (not even the normal vibrate). I deleted the purchased ringtone from my phone and selected just one of the sorry ones that comes on the phone and did a simple restore, but it still would not ring. I trouble shot via chat with an Apple tech last night and he recommended a complete restore to factory settings. I've done that twice and still the phone will not ring or play alerts. YouTube videos and music play perfectly fine, so it isn't the sound card. Has anyone else encountered this problem and been able to fix it without having to go to the Apple Store or get it replaced?
Go to Settings > Sounds > and carefully review ALL your sounds settings (scroll through the entire Sounds page and reconfirm enter your settings).
Also, review Settings > General > Accessibility >
I assume your Ringer/Silent switch on the side of the iPhone is placed ON (up).
Since you're stuck, you may as well read the three page thread (link below) about related issues. You may want to look into the issues involving use of Bluetooth and headsets.
I do not use Bluetooth and I've already done all those things several times. I have everything text alerts using one of the standard alerts and I have a single ringtone (sonar). I've even tried using the default ones. They work fine when you check them for each of the functions, but when I call my phone, nothing happens other than the screen pops up telling me I have a call, or I see that someone sent a text. Reading the boards, it looks like this is a fairly common problem. I'm going to take the advice of the Apple Genius Bar lead tech and get Apple car instead of Sprint and then they will just give me a free NEW phone instead of a used one.
Thanks for posting. I do apologize for the delay in my response.
I am sorry to hear that you are having issue with your iPhone 4.
Hmm, let's narrow this down a bit. Can I please have your zipcode and cross streets?
Sprint Social Care Team