2 rows of black sqares on 20x4 LCD

Other Hardware Displays
1

Hi,

I got this 20x4 LCD display a few days ago, but I can't get it to show anything other than two rows of squares, on row 1 and 3.
I have checked and redone the wiring a few times and tested the soldering conections, which all seem to work fine.
I have a potmeter connected to pin 3, the 2 images show the display when the potmeter is 'open' and 'closed'.
I have tried this with an Arduino uno and an Arduino mega.
I have read some things about the screen maybe being bricked, but I haven't been able to find a fix for this.
This is the code I'm using, which is just an example from the liquidCrystal library with an added delay:

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

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  delay(1000);
  // set up the LCD's number of columns and rows:
  lcd.begin(20, 4);
  // Print a message to the LCD.
  lcd.write("hello, world!");
}

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
  lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(millis() / 1000);
}

Thanks in advance,

Jonajurgen

img 1.jpg

img 2.jpg
img 2.jpg940×705 107 KB

2 
void setup() {

  lcd.begin(20, 4);

  lcd.print(0,0) ="hello world";
  lcd.print(0,1) ="2";
  lcd.print(0,2) ="3";
  lcd.print(0,3) ="hello world");

}

void loop()
{
}
3

ieee488:

void setup() {

lcd.begin(20, 4);

lcd.print(0,0) ="hello world";
  lcd.print(0,1) ="2";
  lcd.print(0,2) ="3";
  lcd.print(0,3) ="hello world");

}

void loop()
{
}

Just copying and pasting this gives me the folowing error: lvalue required as left operand of assignment. When changed to

lcd.setCursot(0, 0);
lcd.print("Hello world");

for all four statements it still just gives two rows of black squares.