Dell optiplex 790 window 10 I can't get a display

Hi

Does that mean a black screen on power up?

Does it mean the boot process is fine, but the OS is the problem?

Is this an AI test question?  Iit sure lacks basic info.

1. What connection method is being used?
2. Did you try any other connection methods?
3. Did you try a different monitor cable?
4. Did you try a different monitor?
5. As @anne_droid eluded to, do you get the Dell splash screen on power-up or nothing at all?