Discussion about the Korg PolySix synthesizer

Thanks to everyone here, this is an amazing place. That said, I am completely stumped with my rebuild.

I just recently finished up my KLM 367 rebuild, and everything looks fine. I reused the rare ICs, the clock, and some other parts that made sense to salvage. 

I had purchased this P6 knowing that it had suffered from corrosion on the computer board. It had about 30 blown tracks, all in the common areas. When I received the unit, it did make some sound, but had the typical blown battery issues(all the patch lights were stuck on, a lot of the functionality didn't work, etc). Now after the 367 replacement, I am not getting any sound at all in manual mode. There is no sound read, but I didn't think there would be anything there, as the RAM would be blank. I can tell that the output amp is working because because I am hearing the noise floor, which I can attenuate using the volume knob. The patch computer seems to be working, as I can change groups and patches as it should work. 

Here are some other things I noticed: The MG led is constantly illuminated, and doesn't change when I adjust the rate. Pressing the Unison, arpeggiator, poly buttons, do not appear to do anything at all.

This is the first synth repair/build I have done, but I have been picking up a lot. I have a decent background with computers and some electronic knowledge. This is probably something easy, that my amateur skill set is over looking.

Thanks