I've seen several synths do this. It did it on mine first after I'd dropped some solder on the m/b accidently and got it all cleaned up to where the vco worked again that I thought had died... but then this error honk randomly would go off. I turned honk off and the board functions fine in all respects except I never use the sequencer so not sure about that. But while the honk was going the led's would flicker between play and stop on the sequencer. I tried erasing all and still does it. Has anyone seen this? I think three units I've seen do this so I'm sure it's just something glitched in memory or something..