LED’s Won’t Turn On

Hello Everyone,

Brand new to all of this but I have exhausted all of my options, including reading through old posts of similar issues.

As the title states, the led’s simply wont turn on.

power supply: is 12v 2 amp

leds: https://www.amazon.com/dp/B01AU6UG70?psc=1&ref=ppx_yo2ov_dt_b_product_details

nodeMCU: https://www.amazon.com/dp/B07HF44GBT?psc=1&ref=ppx_yo2ov_dt_b_product_details

The LED’s are 5v 50pc.5v jumper wire is connected to Vin

Ground jumper is connected into GND right next to Vin

And data is connected to D4.

They are all wired to the correct corresponding wires from the LED themselves

I know nodeMCU is powered on because the blue light is on and the chip is getting warm. I can verify in the config that power is connected because the uptime goes up. I set up it all up to use my home wifi, and downloaded the app. I discovered the lights on my network inside the WLED app. I have tried to connect the data wire to D2 and that still didn’t work.

The only thing I noticed was that inside of LED preferences the LED number is preset to 30 and I can’t change that. Technically it should be 50?

Anyone have anymore troubling shooting ideas? Any help is greatly appreciated!

imgur /a/KwjrKGD sorry for the Imgur format, it won’t let me post more than two links

Hate to say this, but if you’ve wired 12V to 5V LEDs, they are almost guaranteed (98%) to be destroyed.
12V into the nodeMCU gets dropped down to drive the MCU (actually down to 3.3V) but the LED power output will still be the same as the main supply.

You’ll likely need a new strand of LEDs.
You could get the 12V versions of what you listed there.
You’ll also want to look into a proper levelshifter to guarantee the data for your LEDs.

Any example of the wiring?

I also blew up my first LED strip with a 12v supply, easy to do if you are new and don’t check it.

Id Hope this wasn’t the case here, but all informations are leading to that

Ahh crap haha. Something simple that I over looked! I have a converter (not sure what they are called) that can take the 12v and convert it down to 5. I should have just done that originally.

At most it was on for 2-3 minutes before I switched it off. I didn’t notice anything out of the ordinary like burning, smell, or a flash so I hope I didn’t burn them out. I guess we will see when I wire the converter later today.

Should I be worried about the nodeMCU or it’s probably just the LEDs?

Thanks for the replies though guys, really appreciate it

Depends on what voltage the NodeMCu had gotten.
The Max. Is 5Vin. Everything above could damage it and most Cases the voltage regulator fails and occasionally you have may some luck of swapping the regulator and get it working again.

And also this could potentially kill these LEDs too. I mean 12V is more than the max. Voltage of 5V.

The good thing is when they’re getting damaged and glowing white or in any color without having data signal but chances they might fail without lighting up are potentially higher so … I would bet that 2A are more than enough causing damage

Max Vin on the MCU depends entirely on the board. 5V is safest, but if you can login to the WLED GUI, that’s a good sign.

Those epoxy module LEDs will hide their death pretty silently, but - “it’s dead Jim”

Looks like the ESP survived!
Then now the question is „Did the survived LEDs too?"

Well maaaaybe, but I wouldn’t hold my breath.
As I mentioned, there’s a chance the MCU can handle 12V (I’ve a few boards that are just fine with it and some that just go “poof”).

If you keep things down at 5V, the MCU will be happier overall.

Reverse polarity with high amperage would cause more harm probably

Reverse polarity is very often instantly fatal to electronics.
Amperage just comes from what the PS is capable of.

The circuit is typically just as dead from a 100mA or 10000mA supply, the only difference is how much smoke you might generate…

1 Like

Well, finally had some time to wire up the little device that converts it down to 5v. Extremely high likelihood that you were all right and I blew them out! I was able to get them to turn on, but only 3 out of 50 worked. And they were a weird blue / green color. I couldn’t control them at all.

Time to buy some new ones and try it all again!

Thanks for all of the info

Maybe not,
Seems your data signal gets Lost somewhere and some LEDs got damaged but here are few things you still could try:

You might could cut off the defective part and try again.

You also could if legth is somewhat more important replace the Faulty LEDs.

In my case it worked by replacing the Faulty ones.
but on the other hand you’ll never know How Long the other LEDs would last.
(Only recommend when Most LEDs still work)

Afterall the safest and most reliable option is still buying a new one.