I have a very basic circuit on a breadboard using an Arduino's 5V+Gnd to power a few LEDs. All the LEDs are from Sparkfun and rated at 2V/20mA, coming in Red, Green, and Yellow. I'm using 330 Ohm resistors but I also have much higher resistors like 10k and 330k Ohm for testing this issue.

Only one LED is being connected at a time using the individual lanes. Nothing is connected to the power and ground rails on the breadboard. Red, green, and even my white LEDs work great, but so far 5 yellow LEDs in a row have immediately burned. I double-checked wiring, moved wires and LEDs, and went all the up to a 330,000 Ohm resistor, but no luck with the yellows. Is this likely a bad batch of yellow or am I missing a key component?

EDIT: Here is the full board (the wires are complex because this will be an electronics puzzle in a game):

Photo of entire circuit

And here is with the other wires removed to show what's actually connected:

Photo of relevant circuit section

  • 3
    \$\begingroup\$ Can you add a schematic and a photo of your board? \$\endgroup\$
    – HandyHowie
    Jul 10, 2019 at 14:16
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    \$\begingroup\$ Burned? Caught fire? turned to dust? \$\endgroup\$
    – Andy aka
    Jul 10, 2019 at 14:21
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    \$\begingroup\$ If you're burning out LEDs on a 5V supply, with a 330 ohm resistor in series, then you must be wiring it wrong somehow. Most likely, the 330 ohm resistor isn't really in series with the LED. \$\endgroup\$
    – Simon B
    Jul 10, 2019 at 14:23
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    \$\begingroup\$ "After the smoke clears, check the wiring again" \$\endgroup\$
    – Barleyman
    Jul 10, 2019 at 14:25
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    \$\begingroup\$ 99.999% sure you are wiring the resistor in parallel... If an LED is dying with 330k then the wiring needs to be looked at \$\endgroup\$
    – user16222
    Jul 10, 2019 at 14:41

1 Answer 1


Those resistors aren't doing anything at all. All the pins in a row are connected together.

  • 7
    \$\begingroup\$ There it is, I'm a dummy! Thank you. \$\endgroup\$ Jul 10, 2019 at 14:43
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    \$\begingroup\$ The human mind is a wonderful thing. It expects the row of terminals to be connected through in the bits it wants connected and open where it wants it open. I'm sure there's a psychology thesis in there somewhere. \$\endgroup\$
    – Transistor
    Jul 11, 2019 at 13:30
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    \$\begingroup\$ @ Toby - The LED sacrificed itself to protect the Arduino output \$\endgroup\$
    – DaveM
    Jul 11, 2019 at 14:55
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    \$\begingroup\$ @JonathonIrons Look at your other wirings: they're NOT in the same row (except maybe white, which looks like it should burn?) \$\endgroup\$
    – Mars
    Jul 12, 2019 at 5:36
  • 1
    \$\begingroup\$ @Mars I think you need to look closer, they are all wired the same. \$\endgroup\$
    – HandyHowie
    Jul 12, 2019 at 8:29

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