I'd check for bad solders on power supply; I already had this with my 1000PX (same board).
To: vintagesynthrepair@yahoogroups.com
From: lynnreid@...
Date: Thu, 23 Dec 2010 20:22:09 +0000
Subject: [vintagesynthrepair] Kurzweil K1000
Hi...I have a Kurzweil K100. Two notes have stopped working...and the onboard sounds have long since stopped working. I have been using it as a midi controller. Thanks in advance for any help!
Lynn