LCD Pin 5 to ground causes board to shut down - no text output also

First problem: I can’t print anything to my LCD

Second Problem: If I plug in R/W (PIN 5) to ground as all tutorials are telling me to, the arduino and lcd both fade and turn off within 2 seconds of connection to power. If I disconnect pin 5 the LCD turns on and the board stays on and both are lit up indefinitely (except no text can be written). Pictures below followed by code.

Images link - couldn’t get them to embed: Imgur: The magic of the Internet

Code below:

#include <LiquidCrystal.h> 

LiquidCrystal lcd(11, 12, 2, 3, 4, 5);

void setup() {
  lcd.begin(16, 2);
  lcd.clear();
  lcd.print("hello, world!");
}

void loop() {

}

Pin-5 of the LCD is the Read-Write/ pin. It must be at LL-state for write operation. Try by connecting the Pin-5 with DPin-8 of UNO and including the following lines in the setup() function:

pinMode(8, OUTPUT);
digitalWrite(8, LOW);

If the problem exits, try use another LCD Module. I have been using my all LCDs all the time Pin-5 solidly grounded.

I disconnected pin 5 from ground and then I connected pin D8 on arduino to pin 5 of the LCD and ran the code you posted.

void setup() {
  pinMode(8, OUTPUT);
  digitalWrite(8, LOW);
}

void loop() {

}

I verified upload of sketch. Then I plugged pin 5 into ground and it did it again. Measuring 5 volts coming out of pin 5 of LCD. Do you think it's a bad LCD?

Unfortunately I live in Korea and no DIY shops here so Amazon in 10 days to replace it...

Sorry!
Connect Pin-5 of LCD with D8 of UNO and then upload the following sketch. Check that the message hello, world! has appeared. Do not remove jumper of Pin-5 from D8.

#include <LiquidCrystal.h> 
LiquidCrystal lcd(11, 12, 2, 3, 4, 5);

void setup() 
{
  pinMode(8, OUTPUT);
  dugitalWrite(8, LOW);

  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("hello, world!");
}

void loop()
{

}

I left D8 plugged into LCD 5 and uploaded your sketch.

It does not appear. I just have white boxes in the top row (contrast at max) or nothing if I turn down contrast. Here is the image: https://imgur.com/a/lu9lF

I ordered a replacement LCD in case there’s something wrong with it. Should it be outputting 5 volts the entire time from pin 5 on the LCD? And why would that, going into ground, cause the board to die?

If the replacement LCD fixes it I will post an update. Thanks for all the help.

This is a normal picture of a healthy LCD?

Now, you may carry out the following steps while waiting for the new LCD.

1. Change this line LiquidCrystal lcd(11, 12, 2, 3, 4, 5);
with this line LiquidCrystal lcd(A0, A1, A2, A3, A4, A5);
(we are just suspecting some bad ports?)

2. Connect the Pin-4, 6, 11, 12, 13, 14 of LCD with A0, A1, A2, A3, A4, A5 of UNO respectively (we are checking that there is nothing wrong with Arduino UNO itself).

3. Rerun the sketch.

4. Bring the contrast to minimum position so that the display becomes blind.

5. Now, slowly adjust the contrast pot and brings the display into light. Could you see the message : hello, world!

How about a bad breadboard?

Don

Yes! The breadboard should be suspected. In the next step of trouble shooting, direct jumping is to be made between the LCD pins and the UNO pins.

Hey I finally moved back to America and tried a different LCD screen. The new one doesn't kill all power to the board (though I still can't get the damn hello world working). Anyway when I swap LCDs and power on the old one kills everything with the same wire connection as the new one - so I'm sticking with this new one and moving forward with my project.

Just wanted to update since you made an effort to help me. Thanks again.