phone pulsate, and stays on lock screen

[Cameo Gonzales1]

My father has the galaxy s8 active, and he has been having some problems with it for the past 2 weeks. When he turns his phone on, the lock screen comes up. When he swipes up to open the home screen it freezes on the lock screen wallpaper. He has to restart it, and then it's fixed. his phone also pulsates the whole time it's on. it will be laying on the table and you can feel the table vibrate. I was hoping someone could give me any advice on how to fix it. It is a refurbished phone from ATT. He damaged the microphone on his brand new one, so they sent him a "new one"

 

[Bl00dRunzC0ld]

Factory reset it. If it's still doing it, reflash the firmware in Odin. If it's still doing it after that then most likely it's hardware issues and would need to be replaced.