74ls164N, fmalpartida LiquidCrystal 3wire -- cannot get this working!

Doing my best to get a 16x2 lcd working with the great fmalpartida LiquidCrystal library under the “3 wire non-latching shift register” schematic. Unfortunately, I can’t seem to get it working. I burnt a board and was dismayed that the LCD just displayed a row of blank boxes, so I tried recreating it with a breadboard only to have it do the same thing. I’ve tried swapping out shift register chips to no avail, and I reconnected everything in the “4-bit parallel” mode and the test code ran like a champ, so the LCD is working. But I can’t for the life of me get it working in 3-wire SR mode.

Any clues on how to test or fix? I realize the snapshot is a forest of jumper wires; there’s rarely a good way to take a picture that looks particularly clear. The backlight and dimmer work fine, and I’ve tested connections. I feel like I must be missing something pretty darn obvious, but it’s sure not obvious to me :slight_smile:

test code (commented out lots of the sample code just to keep things simple):

#include <Wire.h>
#include <LiquidCrystal_SR.h>

//LiquidCrystal_SR lcd(8,7,TWO_WIRE);
LiquidCrystal_SR lcd(5,6,7);
// order is data (SR), clock (SR), LCD enable
void setup(){

  lcd.begin(16,2);               // initialize the lcd


  lcd.home ();                   // go home
  lcd.print("LiquidCrystal");//_SR");
  lcd.setCursor( 0, 1 );
  lcd.print("Blorp");
}

void loop(){
  lcd.home ();                   // go home
  lcd.print("LiquidCrystal");//_SR");
  lcd.setCursor( 0, 1 );
  lcd.print("Blorp");
}

Urgh, didn't notice the separate "displays" board. Reposting there; mods, please delete this (I've tried and can't).