If it says that it's playing, it should be. Just to be sure: you get to the correct screen by going right at the start of the level, then it's the third door from the left (the first door is a staircase up, the second door is a screen with Jimmy and Buck on the couch). If you want to try resetting it, you can leave the cineplex; that should flip the projector off, then you can go flip it back on, but that shouldn't be necessary.