This message is from bobgrieb <bobgrieb@...>
Sorry Bob. Your message is still filled with that formatting stuff.
Royce
The DSS-1 has 8 voices, so it's possible that one is not working. That could also cause every 8th note to not sound. If it's certain keys that are not working, then that is one thing. But if it's every 8th note, regardless of which keys are causing them to play, that's a voice issue. I see you are not getting MIDI out either. Hadn't noticed that. So I guess it is not a bad voice. I grabbed the service manual from the web. On pdf page 14, you can see three connectors for the keyboard. Two are driving the contacts (a pair for each key) and one is sensing. Before you replace the keyboard, you might want to do a little troubleshooting to make sure it isn't one of the three chips instead. Looks like IC5,6,7. You should be able to use jumpers instead of the keyboard and play notes. The keyboard is just a bunch of switches. Use jumpers with series diodes as well to mimic the keyboard circuit. Probably the DSS-1 code expects the first contact to close, then the second one. That would mean a jumper from one pin of connector 24, such as 24-1 to one pin of 23. Put a diode in series with the jumper, with the anode towards connector 23. Then after you have made that connection (and are keeping it made) place a second jumper from the same pin of connector 25, such as 25-1 to the same pin of connector 23. At this point a note should play. Actually, it might be best to connect the two diode cathodes to connectors 24 and 25 first. Then connect the anodes together and hook them both to the pin of connector 23 at the same time. That would simulate a fast key press, unlike connecting them one at a time. That should make the note louder if velocity is enabled. By connecting the anodes to each of the 8 pins on connector 23 in turn you can see if all 8 inputs are working. Likewise, by moving the other ends of the jumpers to 24-1 and 25-1, then 24-2 and 25-2, etc, you can see if all 8 of the driving circuits are working. If one signal is out, then every 8th key will not play. Of course, it could also be a trace on the keyboard pcb itself that has corroded through because someone spilled something years ago. That's pretty common. If you know which keys are out, then use an ohmmeter in the diode position to check continuity (through the diodes) from the key contacts back to whatever connector is on the keyboard, or wherever the cable hooks to it. The polarity has to be correct on the meter leads of course, to forward bias the diode. Hope that helps.