I was uninstalling an app that i regularly use and my phone shut off and began to vibrate every 3ish seconds. It happened before so i took out the battery, except this time, taking out the battery didn't work. I read online to fidget with the power button and it worked. After it began working, i put my phone sideways and it shut off and began to vibrate again. I then put the phone straight and restarted it again and then it worked.
What is wrong and how can i prevent this from happening? I don't have a backup phone and this phone is not under warranty.
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