Vintage Synth Repair

> hi all.
> new to this group, was hoping somebody out there can help me with
> a repair .... one note is striking at TOP volume. 

One key playing at maximum volume is sometimes caused by a dirty key 
contact.  Some synthesizers use two contacts per key to sense how 
fast a key is pressed - one contact is designed to close before the 
other, and the time between them is proportional to how fast you play 
the key.  If one contact doesn't work properly, you sometimes get a 
key that always plays very loud.