A strange issue I noticed was whenever I hit the reset button on the board, I couldn't send any characters to the EP8266 over the serial REPL interface.  I probed the TX pin on the CH340 (usb to serial chip)/RX pin of the ESP8266 with a multimeter and saw nothing on voltage and frequency settings.  A few days later, I got a cheap logic analyzer as a gift and installed Sigrok and used it to further confirm the lack of any activity.

At this point, I though that it's either the ESP8266 module or the CH340 chip.  There were two 470 ohm series resisters between the two parts so what I did I remove them which allowed me to hook up another usb-to-serial converter to the ESP8266.  The issue persisted.  I started to blame the ESP8266 but there was a vital clue something else was amiss. On my usb-to-serial converter there's an activity LED light when there's activity and it wasn't lighting up at all. Could it be the fact that nothing is being sent to the usb-to-serial converter chip in the first place? I restarted my terminal program PuTTY, and everything was working again!  I used another terminal program, hit the reset button, and it was still working fine.

I'm not sure why hitting reset on the board would cause PuTTY not to send characters.  It was an odd twist for sure.