Hello. My name is ***** ***** I can help you with your problem. For test purposes, set the screen timeout to 30 seconds. Then turn the phone on under battery power with more than 50% charge. Does the phone stay on long enough for the display to timeout and turn off--i.e., phone on, display off?
Are you talking about turning the phone on and starting the operating system or just turning the display on, when you say that the phone turns itself off after less than a minute? When the phone turns itself off, does it turn the display off or does it shut down?