my Macbook pro turns on, logo appears, then screen goes white

About the screens you see when your Mac starts up - Apple Support

Try a SafeBoot https://support.apple.com/en-us/HT201262

Try resetting the SMC http://support.apple.com/kb/ht3964

1 Choose Apple menu > Shut Down.

2 After your Mac shuts down, press Shift-Control-Option on the left side of the built-in keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds.

3 If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button.

4 Release all keys.

5 Press the power button again to turn on your Mac.

Boot into Recovery (Command R) and from the dropdown menu: Utilities> Disk Utility> run the First Aid on your Macintosh HD. If errors are round and repaired, run again until no errors reported.


Recovery http://support.apple.com/kb/HT4718

Try an SMC reset:

https://support.apple.com/en-us/HT201295

Try starting up in Safe Mode:

Use safe mode to isolate issues with your Mac - Apple Support

If neither of those work boot into Recovery and Reinstall Mac OS.

About macOS Recovery - Apple Support

Try Single User Mode (hold command-s keys)

https://support.apple.com/en-us/HT201573

At the prompt, enter this command:

/sbin/fsck -fy

Press the Return key.

This will check your directory and report that it was OK or repaired. Then enter this command to startup normally:

reboot

If none of those work make a Genius Bar appointment for a free diagnostic:

Genius Bar Reservation and Apple Support Options - Apple