Vintage Synth Repair

Hi guys,

I hope someone can help me fix this wonderful module.

There is NO sound coming out of this unit but it powers up & every
thing else works perfect.

I purchased this module with the intent to repair but do not know
which component has blown or died. 

I opened it up & there are no obvious signs of component damage.

I hope someone can suggest possible faliures.


Thanks


Jaz