I'm having some troubles with a parallel connection Pololu 16x2 LCD. When I bought it, it worked fine! The next time I mounted it, it didn't worked; only two black bars appeared on half of the screen.
Some of the things I've already tried are:
- change the pins (first time I used the pins from LadyAda's guide, here);
- delay the first write on the LCD (put a delay() on the end of the setup() function);
- used a power supply instead of the USB to power the Arduino (maybe it could be a power problem...);
- made a new board for the connections, because the first time I tried the display it was on a breadboard and it could have some bad connection or something like that;
- used another library (LCD4bitLibrary).
I noticed that on the back of the LCD there is place for 6 resistors (R1 to R6) and the R6 is "missing"; don't know if it should be there or if it shouldn't; it doesn't seem like that any resistor has been soldered there. I couldn't find any picture of the back of the LCD, so I can't confirm this.
Can anybody point me a solution or a tip for some other thing I should try? Can it "broken"? I'm using Arduino 0022 IDE.
I also uploaded 2 photos for the described problem: one with the black lines and other of the back of the LCD with the resistors (sorry for the bad quality of them…).
Resistors (R6 is the top resistor on the right side):