LED is oozing goo

[williamnumismatics]

Hi guys,

Today when I plugged my LEDs into the power suply, they started sizzling as I could here them. Then they started oozing a black liquid and crackings sounds started appering from the LED. Does anyone know what has happened? I have thrown away about 10 LEDs so far. I don't want this to continue.
Thanks for advice

[camsysca]

you either have an AC supply(could be a DC supply gone bad, or you picked up the wrong wall wart from the junkpile), or you've forgotten to put series resistances in to limit the current through the LED.

[DaveX]

Add a current limiting resistor.

R=V/I

[williamnumismatics]

Hi this happened because I wanted to test if my LEDs still worked. Can you please check my setup to make sure that there are no errors! I have a power supply module connected. I think that my power cable is causing all the trouble.

[LarryD]

• Wire simple LEDs as D1 and D2 are wired.

[LarryD]

• Why are you mixing 5V and 3V3 ?

• Show us how the LED was inserted into the breadboard.

[williamnumismatics]

I pyt the Anode of the LED to the resistor and the red wire and the cathode of the led to the black wire which went to gnd

[LarryD]

• Sounds like you then had the following.

+5v——Anode[>|]Cathode——GND

+5v——[resistor]——+3v3

• You basically had no series resistor for the LED, hence it burned up.

[LarryD]

• You want.

+5v——Anode-[>|]-Cathode—— [resistor] ——GND

[TomGeorge]

Hi, @williamnumismatics

Do you have a DMM? (Digital MultiMeter)

Thanks.. Tom..

[DaveX]

3.3 and 5.0 swapped, but yeah.

Zooming in the on the picture, the potential circuit it looks much more confused than that:

+3.3V -+-- R ---- +5V
       |
       +-- LED -- GND

[LarryD]

• OP, do you understand how the power supply is configurable ?

[DaveX]

@LarryD

do you understand how the power supply is configurable ?

Oops. I didn't in #11. You were right about which was 5V and which was 3.3.