hi. my own zte phone was completely low, at 0%. I tried charging the whole night thinking I will use it the next morning, it could not come on. just now, I was reading the solution. press the volume up and power button for 15 seconds, I did that, still nothing. I decided to charge my phone using my laptop first, then , pressed volume up and power button for 15 seconds. next thing it vibrated and started to charge. I appreciate all your solutions, thanks.