20x4 Display, works rows 1-2 first 8 blocks, but the rest are just white?

I’m using the following script

*/

// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
// set up the LCD’s number of columns and rows:
lcd.begin(20, 4);
// Print a message to the LCD.
lcd.print(“hello, world!”);
}

void loop() {
// Turn off the display:
lcd.noDisplay();
delay(500);
// Turn on the display:
lcd.display();
delay(500);
}

I’m new to all this so I’ve probably missed something obvious, I’m also unable to identify the LCD, as it was given to me, there are no markings or anything on it :confused:

Any help, greatly appreciated :slight_smile:

I'm new to all this so I've probably missed something obvious, I'm also unable to identify the LCD, as it was given to me, there are no markings or anything on it

Your code and wiring are obviously OK since there are characters displayed where they should be.

The display is probably defective. In this case your main controller is working properly but the four auxiliary controllers do not seem to be doing their job.

Don

I'll second that.

We know of no programming error that can cause that effect - the display is defective, has lost communication between the "Master" chip and the three "slaves".

Unfixable.

Return it as defective, to the supplier, for replacement or refund.

Thanks Floresta and Paul_B, I'll get a new screen ordered :slight_smile: