By not boot do you mean that when you try to turn it on nothing happens (no lights, no logo, nothing on the screen) or it boots but you see the motorola logo and "RSD" at the top of the screen? If you are seeing "RSD" at the top of the screen then you should be able to flash the phone.
The phone boots but it stays at the Motorola dual core technology screen and it says RSD protocol and battery is to low to flash. But ivee had it connected to the charger for hours. But I will try out what you said if sprint still refuses to fix it. Thank you for your response.