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Chris Fonville
 
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Default hd4780 LCD problem

This is my first LCD and I am not having much luck. I have checked over
my wiring many many times and cannot seem to find the problem. It is a
4x20 hd4780 LCD. When I turn it on the backlight comes on and I receive
the test signal, but some lines are missing. The top 4 squares, or I
guess pixels, are on but then the next 2 down are not. The bottom 2 are
also on. Here is an example of one character:
*****
*****
*****


*****
*****
This is repeated for each character on the 1st and 3rd line of the LCD.
Is this a bad LCD or do I have my wiring wrong? Also, I can use LCD
Smartie and the LCD will respond but I can only make out some
characters, but most of the screen is gibberish. How can I go about
fixing this problem? Any help will be appreciated. Thanks,
Chris