LCD 7 Segment Display Digital Alarm Clock Display

[bjled]

Hello. I am very new to electronics other than a course I took in College a decade ago. I have been DIY modifying a fish tank alarm clock and in modifying the device the display of the alarm clock and time portion took a turn for the worst. It still works, but the contrast is way off on it now. Basically, the segments that are supposed to be lit are lit, but the segments that aren't supposed to be lit must have some lighting because it is really hard to read. It is easier to read if you read it at an angle and if you backlight it with LEDs.

I have Google searched all kinds of things over a few weeks and I can't find anything on this problem. I am not sure why it is happening. I can post pictures if that would help. Anybody have any experience with these and what this could be? I bought a second unit to test one that is brand new and that one isn't like that. You can read it face on with no problem. I can post pictures if you guys feel like that would be necessary. Sorry for being so elementary for now and new! I do know some things, but don't know exactly what to say yet. It is powered by 3 AA batteries.

Any help would be very much appreciated!

 

[D.A.(Tony)Stewart]

There is a bias voltage pin for contrast on LCD's and maybe another that affects polarization angle. Look for this.

 

[bjled]

There is a bias voltage pin for contrast on LCD's and maybe another that affects polarization angle. Look for this.

Fantastic! This is a huge help. I know that there are your regular positive and negative wires, but there is also a green wire. This might be the one, but the green wire goes from the circuit board to a screw, so I was assuming that it was some kind of an additional ground. I want to say that the connection point on the circuit board says "ID". Perhaps when I re-soldered the wire to the screw it doesn't have an appropriate ground?

 

[bjled]

Thanks for your help! This has been resolved! I did have two pins reversed.