I'm assuming here that you're talking about the Neo Geo MVS system, not the home console.
The battery that stores the time and date is probably flat. Which board do you have? Without a cartridge in a slot, you should get the self test patterns and hardware setup screens. You don't need a memory card.
Even with a dead battery, the game should still load. Try cleaning the cartridge edge connectors with alcohol on a q-tip, and firmly seating it in slot one, then power up the machine.
-Ian