How to check Leakage LEDs in a LED Matrix

Question

Is there any method to check the leakage LEDs in a LED matrix?

I’m building my own matrix by using unbranded cheap Chinese OVAL LEDs. They have no datasheet/specs.

*Some LEDs lights up but take lots of current (like a short circuit).

*Some LEDs current passes when they are reverse biased.

Due to the above scenarios, when my matrix working I see inactive LEDs lights up slightly. I tested individual LEDs by using an analog multi-meter(X1K range).

*When I see the pointer moving both sides, then the particular LED has a problem. I replace them.

*Some LEDs I see the pointer moves more than others, means it takes more current than other LEDs. I replace them as well.

Now the problem vanished & I get a nice display.

I have 512 LEDs in each matrix block, Is there any easy method to check those leakage LEDs in a matrix?

Answer 1

Possibly by checking the voltage drop across each LED, I thought that a diode (Light Emitting Diode) is basically a short circuit in one direction (polarity) and needed some resistance in the circuit to limit the current flow.