Yesterday I bought some old stuff that were basically leftovers from a shop. I knew who the guy was from before (I've spent money there when I was younger...).
He had a pile of different synthesizers in various condition but the ones I was interested in were a JX-3P with PG-200, a Matrix 6 and a Poly 61.
The JX-3P was working (I tried it) except for the lowest C-key which was not responding. The volume knob was scratchy (normal) and some slider caps were touching the front panel. The PG-200 was working he claimed but he didn't have the cable which connects it to the JX there at the time.
The Matrix 6 was a 120V-machine (we use 230V in Sweden) and he said it's only making a constant tone when it's powered up. Furthermore a key in the middle of the keyboard is broken off in half and another key is cracked and kind of "hanging" there but ready to fall off.
I took a look inside and noted that all the six CEM3396 chips were there.
The Poly 61 started up and the panel buttons responded. Buttons 2 and 5 I think were really really tough to get any response from though. Some buttons were "bouncing".
However, it doesn't make any sound at all. It's completely silent.
I bought all three for a fair price with an option to return the two faulty ones for some money back within two months if I wasn't satisfied. Fair deal.
He also promised he would send me the programmer cable for the PG200 along with the other half of the broken key for the Matrix 6 which he said he spotted in a box in his home. I trust he will do this but you never know :) I might end up replacing the key altogether anyway but the cable would be nice.