Reel to reel problem

I recently purchased a second reel to reel machine, purely for playing some small reels which are recorded at 1 7/8 inches/second. It is a Sanyo MR-212. I changed the belts, and had to do a small modification to keep it in play mode only, due to the fact that the plastic slider which is used for switching between play and record had broken due to age. I don't have any intentions of recording using this machine. Now, the current problem is that although the speaker comes on when I select Play, it doesn't produce the sound recorded on the tape. Is there perhaps a faulty component? I have attached two pictures, as well as the schematic for the recorder.