To troubleshoot a black screen on a computer, you can try the following steps:

1. Check if the monitor is properly connected to the computer and turned on.
2. Restart the computer by holding down the power button until it shuts off, then turning it back on.
3. If the computer boots up but the screen re ins black, try connecting the computer to a different monitor to see if the issue is with the original monitor.
4. If using a laptop, try connecting an external monitor to see if the issue is with the laptop screen.
5. Check for any loose connections or da ged cables between the computer and the monitor.
6. If none of the above steps work, you y need to seek professional help to diagnose and fix the issue.

If the issue persists, it could be related to hardware failure or a more serious problem with the computer.