To reset your MacBook Pro white screen on startup, here's how: 1. Restart your Mac and immediately press down Command + Option + Shift + R keys together to enter into macOS Recovery mode. 2. Choose Disk Utility, click Continue, select Macintosh HD and click Erase from Disk Utility's toolbar. 3. Name the volume and leave the format as APFS. Use GUID Partition Map as Scheme. 4. Click Delete Volume Group to delete Macintosh HD, Macintosh Hd Data, and any other volumes you created. 5. Click Erase to confirm. 6. Select Reinstall macOS in the macOS Utilities window and then follow the onscreen instructions to reinstall macOS.