Arduino Forum

Using Arduino => Displays => Topic started by: jmpcm on Jan 31, 2011, 01:43 pm

Title: Pololu LCD 16x2 display problem
Post by: jmpcm on Jan 31, 2011, 01:43 pm
Hi guys!

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:


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…).

Black lines: (http://flic.kr/p/9ewkiv)
Resistors (R6 is the top resistor on the right side): (http://flic.kr/p/9ezqpq)

Thanks!
Title: Re: Pololu LCD 16x2 display problem
Post by: liuzengqiang on Jan 31, 2011, 04:45 pm
I wish to help but can't see the picture from the broken links. Try reposting the pictures, disconnect all the wires and only leave gnd and 5V. If black boxes don't show and instead stripes show, the LCD is damaged, possibly near the conducting rubber. Maybe servicable.
Title: Re: Pololu LCD 16x2 display problem
Post by: jmpcm on Jan 31, 2011, 04:59 pm
Hi liudr!

Sorry for the links. Here it is for my flickr set: http://www.flickr.com/photos/jmpcm/sets/72157625945346394/

I've already tried to connect only VDD and GND (pin 2 and 1, respectively) and appears the bars I referred. What do you think?

Thanks a lot!
Title: Re: Pololu LCD 16x2 display problem
Post by: liuzengqiang on Feb 01, 2011, 08:19 pm
Such a clear-cut block-no-block image! I think maybe one of the controllers in the back (the two black epoxy bumps) is dead or its connection to the lcd panel is bad. The rubber between the circuit board and the lcd glass panel might be dislocated. How do they look?

Refer to figure 1 here:

http://www.altadox.com/lcd/knowledge/lcd_connection_types.htm