Arduino Pro Micro TX and RX leds flash quikly while power drawn from VCC pin
Aah, I figured it out! @JeffWahaus was correct, the RC RX was placing too great a strain on the Arduino Pro Micro. My latest working theory is that when the RC RX is in communication with the RC TX, it has current spikes that allow the system current draw to exceed that required to drop the voltage coming out of the 5V regulator below that required to shut off the ATmega32U4 MCU.

The solution I found, upon recommendation, was to move the RC RX voltage source from the VCC pin to the RAW pin which taps power from ahead of the 5V regulator and add a 10uf capacitor in parallel with the RC RX to smooth out any current spikes.







simulate this circuit &ndash; Schematic created using CircuitLab