Geeetech

Thank you.
I tried the Sketch in the link you supplied.
Since it was for a 16x2 display, I changed the code from
LiquidCrystal_I2C lcd(0x27,16,2);
to
LiquidCrystal_I2C lcd(0x27,24,4);

Either way, it does not work. I get the same result as I specified in my first post.
Sample Sketch for 24x4 ...

I don't have picture. I have checked connections. They are OK.
Please just send sample Arduino Sketch.

I'm having trouble getting this display to work. I am using it with an Arduino Uno and an Arduino Duemillenova with the same result. I have loaded a "Hello World" test Sketch. The unit displays two rows of block characters (all pixels on) on the first and third rows. The backlight will blink once ...

Just got this 20x4 LCD board (JND2004A) with your GEEETECH LCD1602 Serial interface module. I can't get it to work with any of the sample ("Hello World") Arduino sketches I can find on line. All I get is 2 lines of block characters (all pixels on) - looks like the first and third line. The back ...