phone starts up but then constantly freezes then the screen goes black

There are quite a few things that can cause this, but most commonly it’s going to be caused by a third-party app. Either by installing a new app or updating an existing app, you can render your device unusable. Quality has improved drastically over time, but it could still be the case. I would recommend trying to start up in Safe Mode. This will disable all third party apps. If your device starts to run fine in safe mode, then it’s probably an app that is the issue. This is a tedious process, but it might solve your problem. Go into safe mode, remove apps one at a time, each time going out of safe mode, testing, and then trying again with the next app. Alternatively, if you have everything backed up to Google, you can try a master reset, but I know that is a pain. I don’t mind doing it personally because I know everything is going to restore from where I left off, but there’s always a risk not everything will be saved, especially app data. But, it might be worth a shot. Here’s how to go into and out of safe mode:

Safe mode allows you to turn on the device with third-party apps disabled. Then you can easily uninstall apps that may be causing a conflict or software problem.

1. From the Home screen, press and hold the Power button.
2. Press and hold Power off on the screen.
3. To reboot into safe mode, tap Ok. The phone will now reboot into safe mode.
4. Uninstall apps that are causing a problem.

1. While in Safe mode, press and hold the Power button.
2. Tap Power off or Restart. Phone will now reboot back into the normal operating mode.