Lcd display shield, no characters

Question

So, I've been trying to make an Lcd display shield I got from ebay to work with arduino. Using this very simple code:

#include <LiquidCrystal.h>
#define RSPin 8
#define EnablePin 9
#define DS4 4
#define DS5 5
#define DS6 6
#define DS7 7
#define LCDColumns 16
#define LCDRows 2
LiquidCrystal lcd(RSPin, EnablePin,DS4,DS5,DS6,DS7);
void setup()
{
 lcd.begin(LCDColumns, LCDRows); //Configure the LCD
 lcd.setCursor(0,0);
 lcd.print("Hello, World!");
}
void loop()
{
} 

Actually I've tried several simple examples, checked pins physically to make sure I'm using the right order, But no luck. backlight is on, no characters at all. Am I missing something? Or should just contact the seller to send another shield.

• KIIV: My guess: wrong contrast settings (on blue potentiometer)
• shdow: I've tried rotate it, doesnt seems to do anything

Answer 1

So, after some close inspection I noticed that the blue potentiometer wasnt soldered in correctly. Also, its needs to be turned quiet a lot to have some effect. Might replace it completely. But now it works!

• K7PEH: Usually, PCB based potentiometers require many turns (~25) to cover the full range. If a pot has been used a lot, a poor soldering joint will indeed come loose. A super poor soldering joint comes loose without any help from the pot.