Hi Bob,
I have no oscilloscope as yet, but a nice digital voltmeter and a cool Logic probe by Elenco, both very affordable.
Not too sure how I could use the Logic Probe to detect any faulty IC, but looking to try that, so any help with this is much appreciated.
When I check the voltage sweep from the center pin of the resonance pot (all other pots to 0, i.e. Min value), I get 5V -> -5V (Res 0 to Res 10).
The data pin on the board left to it shows a smaller value sweep: -4.37V to -5V, so I guess that means the multiplexing is working?
When I check the voltage on KLM-367 - IC9-P7 I get the voltage stuck on 0.35V in normal mode, and stuck on 10V in Manual mode.
Yash