Bronica SQ A Viewfinder problem

Ive recently acquired a Bronica SQ A, and today, after having loading it with film, the viewfinder is not showing anything.
It worked a few hours ago and I'm just wondering if anyone can help me out, is there anything that would disable the viewfinder? I've tried all the buttons and whatnot, I just can't fathom why its not displaying anything.
Feel a bit silly asking, but any help would be greatly appreciated!
Cheers

i thought i'd respond tho' i don't own a bronica, knowing how upsetting a new-to-you camera problem like this can be....

mirror locked "up"? shutter problem? battery dead?

You mean the mirror is up? Did you crank it to wind the film? The mirror only returns when you crank to wind the film. It's not an instant-return mirror like in a 35mm SLR. It's also possible that you flipped the mirror lockup lever (right hand side towards the front of the camera) to the "C" position, which leaves it up continuously. You can download the user manual for the SQ-A from here:
http://www.butkus.org/chinon/bronica/bronica_sq-a/bronica_sq-a.htm

On my SQAI there is a little Lever above the rewind crank for multiple exposures. If this set for this function it allows you to cock the shutter without winding the film on. On mine it is set to vertical position for normal use and turned horizontal for multiple exposures. If it is set to multiple exposures the mirror will be locked up. If this has happened turn the switch off and maybe fire the shutter. Just another thought has the shutter fired but the film has not been wound on? After firing the shutter the mirror stays up until the film is wound on.

Tony

I'm sure I had fiddled with the crank before I posted this, but gave that a turn and it sprang into life.

Thanks very much for the replies people, its much appreciated!

Excited to start shooting with the Bronica, there's something about it that's very invigorating, can't wait to see what I create.