Never ran into this before. Switch matrix test shows all switches in rows 1-7 as closed. Disconnect switch wires from CPU board and turn to open (except 24, which is NC).
I have a GLM 16-opto board installed, and it is showing weirdness also. Remove the connection to the CPU board and the issue clears also (same as unplugging CPU board).
Getting 15VDC from the power driver board TP1 (powers the optos, motors, etc.), which is higher than the 12V nominal value.
Any ideas?