Sorry to resurrect this thread however I couldn't get the firmware to compile using
platformio run -e LPC1769
I had a look in the pins_TH3D_EZBOARD.h file and it defines the board as LPC1768. The following worked for me:
platformio run -e LPC1768
In the firmware compilation video on the EZBoard installation page you also mention using LPC1769. Did this change? I'm using the latest firmware TH3D_UFW_U2.R1.5.