You can restore the scope to "standard defaults" by pressing the "storage" button (in the 6 button "MENU" group near the top). Then when the indicators for the buttons alonside the right side of the screen change, you will see the bottom button is labeled "Default", press that and you get back to default settings.
After doing this, if you are trying to display the 1 Khz built in calibration waveform, you will need to move the trigger up, and slow down the time base by adjusting the big knob in the horizontal section.
If you have tried everything and still can't get a display, you could resort to pushing AUTO, just in case someone left the scope in some haywire setup, but that button is poison and should be thought of in that way. The "restore defaults" method is better.
Tom's electronics pages / tom@mmto.org