Power on tube amp without tubes?

Hi gang,

Sorry for what is likely to be the typical "stupid question"....I have a new Cary SLI-80, and the remote function stopped working....I'm checking to make sure no connections came undone, but had to remove 4 large tubes in order to set the amp upside down on its transformers....Can I power the amp on without the tubes, without harming it? This is my first tube amp....

Thanks!