I bought the phone new in a box, never opened, I put the battery in, let the battery drain, then charged fully 100%, but the phone shuts off, I bought a new battery from Amazon and still doing the same, so I know it is not the battery, I googled the issue but no one seems to know how to repair it. I reset the phone from scratch, still shuts off, I don’t think it is the power button. I must be something with the programming, I find the phone is very slow, can not install certain apps, such as my TD Canada trust app or PC card app, anyone know how to fix this shutting off issue?