helloitabot wrote:From where I can see them they don't seem to be caught on the sides of the openings. It just seems like they aren't being pushed down far enough to complete the circuit. But I could be wrong...
I believe the Prophet 600 was fitted with either a Pratt-Reed J-wire or carbon pellet silicon membrane keyboard mechanism (very similar to the Juno-106) depending on when it was built. The membrane type keyboards were fitted to the later 600s. Unfortunately both forms of keyboard are not without their issues.
If yours is a later one see this video for contact cleaning:http://www.vimeo.com/5565712
If it is an early one with a pratt-reed mechanism - like the ARP Omni-2 - then there are a number of failure modes but, since so many of your keys dont work I'm wondering if either the bus bar or the contact wires themselves have become heavily tarnished or if something is wrong eg. cabling.
Can you post a closeup of the offending article??
Promise not to botch your 600 - it deserves better than that