How would I tell if the Kurzweil k2000r I'm considering buying has expansion boards or additional RAM installed?
Do you have access to the machine, or are you buying it over a distance? If you have access to it, simply check the program banks, which will tell you if any ROMs are installed. To check the RAM press the Master button and it will show a screen which will indicate how much RAM is installed. The sample board can be spotted on the back of the machine. From memory it has a single jack socket and two XLR sockets on it.
No problem. Just a point, the factory rom chips are becoming rarer and rarer as are the RAM kits required to expand the memory. However, the K2X series are still incredibly powerful synths unexpanded!