Which LED to USE For LED DISPLAY

[narindia16]

Which LED to USE

I purchased a LED Moving message display with 7 rows and 64 cols. I pluged out the microcontroller p89v51rd2 and inserted mine in that and it is working fine.

My problem starts from here, i replaced one led of that board with a new one. Now new led keeps on which it is expected to be off. and the other leds in the same col shows very slight voltage when they are expected to off. It seems to be voltage or current problem.

I checked voltage accross the led on the actual board. it was nearly 4.68. Shop keeper of LED from which i purchased new LED said it will work between 1.5 to 2 V. But it is glowing with above problem

Please help me guys.

 

[dimas_lilik]

I think your new led difference with old led.
Your old led work On----> 4.55 Volt
OFF ----> 0 - 2.45 Volt
So if you replace with new led use serial with resistor 330 Ohm

 

[pranam77]

I guess you have inserted the new LED in the wrong direction. This will complimnet the Status. Just re-check and revrese it . Good luck