Here's a troubleshooting link from a K1000 users group.
http://k1000.net/problems.htm
I'd advise contacting them for advice.
But NOTE that in their FAQ they mention the battery is soldered in.
DO NOT UNDER ANY CIRCUMSTANCES TRY AND SOLDER LEADS TO A BATTERY. INSTEAD solder in a proper battery holder.
However I'm not even certain if your keyboard is supposed to have a battery.
What did Kurzweil Tech Support tell you?
If Tech Support is stonewalling you then contact the users group I linked in this message. They have a lot of experience with your particular board while I have virtually none with the K1000 series.
Gary
