If you're having trouble with the display settings on your external screen while using the karaoke player, here are a few steps you can try to fix the issue:
1. Check if the screen size is detected automatically by the player. If it doesn't, you can manually change the screen resolution/ratio from your TV/screen settings.
2. Try fixing the issue by reinstalling the setup. Simply take off all the cables and put them back on again to ensure they are properly connected.
These steps should help you resolve any issues you may be facing with the display settings of your external screen.