HTC's Response for the EVO Reboots:
Thank you for contacting HTC America Technical Support with your concern regarding the rebooting of your EVO 4G. I understand how important it is for your device to operate properly and I apologize for any inconvenience this situation has caused for you.
We are aware of the rebooting issue and an MR was released on 09/24/10 to address this issue. Please go to
HTC Mobile Phone Support - HTC EVO™ 4G (Sprint) - Downloads to download this update to your phone. You will choose the third item in the list with the above date. Prior to downloading this material, please click on the word “more” at the end of the descriptive paragraph for details and instructions.
If you continue to experience this issue, it could be the result of a third party application conflicting with the Android Operating System. It is advisable to remove all downloaded applications and this will probably resolve the issue. You can test these apps to see which one caused the problem by adding one back to the device every other day. When you begin to see issues again, you will know the cause is the most recently added application.
If it turns out that third party applications were not the issue, then carefully inspect your battery and the contact points for any damage. If your battery is not completely flat on both sides, it will require replacement. If any of the contacts are damaged in any way, replacement will be necessary. The contacts can be cleaned of buildup by gently rubbing with a pencil eraser, then gently wiping with a soft, dry cloth.
The next step will be a factory reset. Please keep in mind that doing so will restore the device to its original manufacturer settings, erasing all added data. It is therefore crucial to back up all of your information prior to doing the reset. HOME > MENU > Settings > Privacy > Factory data reset > Reset phone > Erase Everything.
If the rebooting issue still persists after completing all of these steps, then you will need to talk to your Sprint representative for details on warranty replacement or repair.