Repairing a Sequential Circuits Six-Trak

Hey there, I was lucky enough to get a Six-Trak for free from someone. I had to majorly clean this thing up since it was clearly in a very bad garage for a long time. Either way now that I have done that I plugged things in so far I get two-zeroes in the display (Seems good) but no sound comes out and none of the buttons appear to do anything. I have some electronics knowledge but I wonder if anyone has any info to get me started?