I got an upgrade about a week ago, a sprint viper. It was functioning fine until yesterday when it suddenly stopped making calls. Everything else still works fine, internet, text, apps, everything. But not my phone. When I dial a number as soon as I hit call it hangs up. No matter how many times I try, it won't call out. I don't have a house phone, and I have no way of knowing if I can't recieve calls either. I haven't gotten a call since this started. I need to know how to fix this, pronto!
Try pulling your battery and power cycling the device and then updating the profile:
If you're still having these issues after, post back and let us know and also post your zip code so we can look at the network in your area to see if that might be the cause.