40x4 LiquidCrystal LCD not responding SOLVED

hello i try to use my 20x4 LCD i haven’t in a while i went to upload a sketch listed below

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x20);  // Set the LCD I2C address

#define BACKLIGHT_PIN     13

// Creat a set of new characters
const uint8_t charBitmap[][8] = {
   { 0xc, 0x12, 0x12, 0xc, 0, 0, 0, 0 },
   { 0x6, 0x9, 0x9, 0x6, 0, 0, 0, 0 },
   { 0x0, 0x6, 0x9, 0x9, 0x6, 0, 0, 0x0 },
   { 0x0, 0xc, 0x12, 0x12, 0xc, 0, 0, 0x0 },
   { 0x0, 0x0, 0xc, 0x12, 0x12, 0xc, 0, 0x0 },
   { 0x0, 0x0, 0x6, 0x9, 0x9, 0x6, 0, 0x0 },
   { 0x0, 0x0, 0x0, 0x6, 0x9, 0x9, 0x6, 0x0 },
   { 0x0, 0x0, 0x0, 0xc, 0x12, 0x12, 0xc, 0x0 }
   
};

void setup()
{
   int charBitmapSize = (sizeof(charBitmap ) / sizeof (charBitmap[0]));

  // Switch on the backlight
  pinMode ( BACKLIGHT_PIN, OUTPUT );
  digitalWrite ( BACKLIGHT_PIN, HIGH );
  
  lcd.begin(16,2);               // initialize the lcd 

   for ( int i = 0; i < charBitmapSize; i++ )
   {
      lcd.createChar ( i, (uint8_t *)charBitmap[i] );
   }

  lcd.home ();                   // go home
  lcd.print("Hello, ARDUINO ");  
  lcd.setCursor ( 0, 1 );        // go to the next line
  lcd.print (" FORUM - fm   ");
  delay ( 1000 );
}

void loop()
{
   lcd.home ();
   // Do a little animation by writing to the same location
   for ( int i = 0; i < 2; i++ )
   {
      for ( int j = 0; j < 16; j++ )
      {
         lcd.print (char(random(7)));
      }
      lcd.setCursor ( 0, 1 );
   }
   delay (200);
}

the address is 0x20 so i uploaded it i use this library https://bitbucket.org/fmalpartida/new-liquidcrystal/downloads version 1.7.1 and the arduino i2c scanner to get the address and when i tried it again the backlight came on with a white cursor blinking every few seconds off and on but no text not sure what’s going on i did this before and it worked this way i really need help can someone please help me?

i try to use my 20x4 LCD

Which one would that be?

i use this lcd from this person i got on ebay http://www.ebay.com/itm/231224391595?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT and i used this serial I2C interface from this ebay listing http://www.ebay.com/itm/321259699324?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT same guy? it worked when i first got it but not right now.

Are you sure the I2C I/O expander pins are mapped correctly?

hello sorry what do you mean?

Have you used this exact software (library and sketch) with the hardware you have?

The I2C device has a number of I/O pins which have to map exactly to the parallel I/O pins on the LCD.
Your LCD constructor is using the default mapping for that library, which may not be correct for your particular LCD.

i have used the library but i just remember that sketch is for my 20x2 lcd i just looked i can't find my 20x4 sketch it's done i just looked at this code and it setup for 20x2 my smaller screen grrr.

not I'm not even sure what's going on or if it's the right library i have but it's the only one i have right now.

i got it to work i had the wrong version of the LiquidCrystal library because i was using another library for my other screen that took a older version i found my newer version and it work thank you. problem fixed