When you encounter a black screen while attempting to switch to Desktop Mode on your Steam Deck, it can be frustrating. However, there is a simple solution to help resolve this issue. Here is a step-by-step guide to solve the problem:

Solution

1. Switch Accounts:

   • First, log in to a new Steam account through the game interface.
   • Use this new account to switch to Desktop Mode.
   • If the switch is successful, delete all files (excluding folders) located at Home/.local/share/kscreen and Home/.local/share/kscreen/outputs.
   • For safety, you may choose to cut and back up these files to another location before deleting them from the original location.
   • After backing up, switch back to Game Mode, log in to the account that had the issue, and try switching to Desktop Mode again. The problem should now be resolved.

2. For Users with Decky Loader Framework Installed:

   • Ensure you have the Decky Loader framework installed and have set a root password in advance.
   • Install the Decky Terminal plugin.
   • Execute sudo -i to log in as root, then run the following commands:

     cd /home/deck/.local/share/kscreen
     rm *
     cd /home/deck/.local/share/kscreen/outputs
     rm *
     exit

   • After executing these commands, close the Terminal and try switching to Desktop Mode again; the issue should be resolved.
   • It is recommended to create a script file named fix.sh containing the above commands and store it in /home/deck/. Remember to make the script executable by using the command sudo chmod +x /home/deck/fix.sh.

By following these steps, you should be able to overcome the black screen issue on your Steam Deck and enjoy a seamless gaming experience.