Thank you in advance for any assistance. I have an HTC vivid on 4.0.3. I know it's out dated but the phone works great except for this one issue that I would like to be able to resolve. About two months ago, I went to make a call and my phone rebooted. This happened a few more times so I figured it was time to do a factory reset. This resolved nothing. The battery was replaced a few months before this started happening. I've talked to AT&T and they were not able to resolve. I've been googling for answers and have only seen one resolution that worked but is not an option on my phone. Someone mentioned disabling Google dialer but I don't have it. I've disabled everything I don't use. I see there is a dialer and phone app. The dialer will let me disable, which I did without any resolution. The phone app does not have an option to disable. Could the phone app be the issue? What else can I disable on the phone that I don't need? Any idea what causes this? This is an intermittent issue although it occurs more frequently. All other functions of the phone work. Update....switched carriers and got a new sim. Still reboots intermittently when making or receiving calls. Had AT&T and switched to Cricket. (whch is on AT&T network) No one has any ideas?