Q: Pressing pushbutton switch KBI5 or KBI6 causes my board to reset
A: The ADC option header shunt at position PTH0 connects the potentiometer at RV1 to the same signal used by the pushbutton switch KBI5. Pressing the switch may cause a VDD to GND short causing the board to reset.
The same condition exists for pushbutton switch KBI6 when the ADC option header shunt at PHT1 is installed.
When using pushbuttons KBI5 or KBI6, ensure the shunt at PTHx is removed. Alternately, do not use either pushbutton switch KBI5 or KBI6 when using potentiometer RV1.
Q: Why are both the GDM-121F and GD-3980 drawings included in the attachments below?
A: The GDM-121F is an assembly consisting of the GD-3980 LCD mounted on a small carrier PCB. Both drawings are attached below for completeness.