pentax k50 viewfinder problem

Hi, The viewfinder on my K50 intermittently shows no image. I was out photographing yesterday - sometimes using live view, sometimes the viewfinder. On several occasions, but not every time, after using live view, when I switched back to use the viewfinder the view through the viewfinder was just black - no image to see. On those occasions where I was shooting in bright sunlight, the live view was not very good because of the light. Switching the camera on and off made no difference. I don't want to have to send the camera back unnecessarily. Does anyone have any suggestions as to what the problem may be?

If you're looking through the optical viewfinder and it's black that means the mirror must still be locked up, as it is in Live View.

Perhaps you didn't switch off Live View?

Thanks for your reply. I was wondering about the mirror. I had switched off live view each time - if not, I should have expected to see an image on the screen. By pressing menu I got the menu but still couldn't get a viewfinder image. However, each time I experienced the problem, I switched off the camera, switched back on and sometimes got a viewfinder image and sometimes not - in which case I had to switch to live view again. As many times as not, when I subsequently switched off live view, I was unable to get a viewfinder image.

Thanks for your reply. I'm sorry if this seems a stupid question but what would the setting be to allow firing off shots without a lens attached. I can't find anything to cover this in the manual.