Weird Bugs using 20x4 LCD with Arduino Uno

We can't check your wiring with the photos that you have provided.

  • We have to be able to verify that you followed the PCB traces correctly.
  • We have to be able to unambiguously follow each wire from one end to the other.

Don

EDIT: With a second look I think you may have D4 - D7 hooked up exactly wrong. The yellow wire from pin 2 looks like it is going to what is probably D4.