Didn't get a chance to go through the list until now.
here's what I've got.
all 32 LED/lamps on the top panel, (under the music stand bar) stay illuminated when the synth is switched on with the exception of the LFO trig. that will only light when depressed.
I started this diagnostic with cn8 and 9 detached. then reattached.
In both cases the synth creates a tone when switched on that decays over 5 seconds.
followed by silence for about 15 seconds and then the tone repeats. again followed by silence, and so on.
it is unresponsive to keys pressed on the keyboard even when cn8.9 are attached.
totally capable and comfortable with a multimeter. would consider myself to have medium electronic knowledge. I have no oscilloscope.
thank you BR!