I own a Minolta SR-101 35mm film camera and have been using it for a while and have had no problems with it. Recently, when I take a picture, the viewfinder goes black (usually when I'm shooting with a high shutter speed). I am by no means an expert when it comes to the mechanics of film cameras, but I thought it may be because the shutter was stuck, but I was able to advance the film, and the viewfinder went back to normal. This has happened multiple times and I have yet to get the roll developed, but I was wondering if this means that the picture was not taken? If anyone could help me or knows why this might be happening, I would very much appreciate it!
(Also please excuse me if I made any mistakes in terminology!)
Flipping the mirror and opening the shutter are two separate actions that are usually coupled, but not necessarily - see mirror lockup.
There are some cameras (mostly medium format - Bronica ETRSi comes to my mind) where the mirror stays up by design, as a sort of poka-yoke reminder to wind the camera again.
While your camera obviously has a malfunction and should be serviced the stuck mirror doesn't necessarily mean the shutter has not fired.