Backlight only worked once

I just bought a 16x2 LCD Backlight display that I am connecting to my Uno.

I started by only connecting the backlight (pin 1 = backlight anode, pin 2 = backlight cathode). Pin 1 was connected with a 220 ohm resistor to 5V and Pin 2 connected to GND. The backlight turned on and then turned off after a few seconds. Now I cannot get it working again.

The part no. is 162B-CC-BC-3LP.

Data sheet: http://docs-europe.electrocomponents.com/webdocs/06dd/0900766b806dda15.pdf

Did I receive a faulty display or what have I done wrong?

I started by only connecting the backlight (pin 1 = backlight anode, pin 2 = backlight cathode). Pin 1 was connected with a 220 ohm resistor to 5V and Pin 2 connected to GND.

As you may have already noticed the LCD displays that have their pins in the lower left corner have a non-standard pin layout so you have to be particularly careful. Your description of the pin connections is correct for your display but the 220 ohm resistance may be too high since the calculated value for a white backlight is around 80 ohms.

What bothers me is the statement that "The backlight turned on and then turned off after a few seconds". One possible explanation is that the series resistance was not connected properly and that excessive current destroyed the LED backlight after a few seconds. On the other hand, from what I have observed from other forum posts is that these LEDs usually survive this kind of mistreatment, possibly because the power supply shuts down. Are you sure that your power supply is still functioning?

Don

I did the same thing, only without a resistor. I destroyed the LED back-light on my LCD. My back-light came on and my display was working for a while. When I switched off and on again later it did not come back on. I opened my LCD and saw the little LED back-light was burned black inside. I used a 162D LCD.

I will be trying to replace the blown LED back-light with a blue or white normal 3mm LED. I will let you know if it worked.

I checked today and verified that the power supply is still working. I can only imagine that the resistor did not have proper contact in the breadboard and thus I supplied 5V to the backlight.

Insert Quote I checked today and verified that the power supply is still working. I can only imagine that the resistor did not have proper contact in the breadboard and thus I supplied 5V to the backlight.

If the resistor wouldn't have a proper contact in the breadboard, the display wouldn't lit. Unless you had it connected Anode to 5V and also resistor from anode to 5V, which would make the resistor completely useless