Do you happen to remember the last note you were working on before the screen went blank? If so, with Obsidian closed, you could try renaming that file in Windows File Explorer or the Finder.
If you are willing, another thing to try (with Obsidian closed) is moving or renaming the .obsidian/workspace.json file in the troublesome vault. This will reset the tabs you had open, sidebar position(s), ribbon order, etc., but may get you back to a working state.