Hello Richard,
You are correct in the assumption that it is not needed for the Nextion display implementation, nor anything else on the ?BITX.
I would check that you have not connected the power for the Nextion to the contrast pin (3) instead of the +5volt pin (2) on the Raduino header.? You did say that there was not a connection to pin 3 of the Raduino LCD header, so that should rule out miswiring as the issue.
Removing the potentiometer would verify if it is the Nextion wiring as the issue as the display will not work.? Before doing that I would remove the power/data connection to the Nextion (low voltage can damage it) and measure the voltage to the power pin while varying the contrast control.? If the voltage changes, it is miss wired.
I would suggest that you find the issue as there could be another problem on the Raduino board if it is not a misconnected Nextion.? If it is a misconnected Nextion, then there is not a need to remove the potentiometer other than to save about 0.5ma or 2.5milliwatts in power (it is a 10k resistor across 5volts).
73
Evan
AC9TU
