ArduinoUno and SainSmart IIC/I2C/TWI Serial 2004 20x4 LCD

Other Hardware Displays
2

I got it right now.

the address was wrong, and that was it.

LiquidCrystal_I2C lcd(0x"Any number", 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);  // Set the LCD I2C address

change that into

LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);  // Set the LCD I2C address

Thanks, hope this helps somebody.