1
\$\begingroup\$

I have a WS2812B strip which, I guess, I ruined it. I connected a 12V adaptor (by mistake) to the strip.

I have a multimeter and when I check the +5v/GND end terminals of the strip, the meter lights up. But when I check the DIN end terminals, the meter doesn't light up. Can someone please help me understand my questions below ?

  • Does this mean the DIN strip blew off ?
  • I connected a high voltage to the +5V/GND which works fine. How did I end up blowing the DIN strip ?
  • Will any part of the wire still work or should I buy a new one ?

enter image description here

So, I cut up a part of the strip and tried checking. Only a part of the lights glow good while others are glowing low or not at all.

\$\endgroup\$
2
  • 1
    \$\begingroup\$ Use a magnifying glass. If the little chip looks burnt or any wires are loose inside the led, it's no good. See i.imgur.com/5jszUPX.jpg for a close up of a good chip. \$\endgroup\$
    – Passerby
    Dec 22, 2015 at 6:03
  • \$\begingroup\$ These LEDs need a data signal so they know how much to light up. If you don't connect the data signal, the picture is normal - sometimes they interpret a little bit of noise as data and they light up randomly. \$\endgroup\$
    – user253751
    Mar 3, 2020 at 11:30

1 Answer 1

Reset to default
2
\$\begingroup\$

DIN is not connected through the entire strip, so that is fine.

I'd just test by giving 5V power to the entire strip and checking that there is only a negligible current flowing (so none of the LEDs are shorting the supply), then giving it a data signal it can understand and seeing whether anything lights up.

If it doesn't work feeding data to the first LED, try the second (because the second LED is fed data from the first, so if the first one is dead, the rest of the strip won't light up either).

Test your data signal against a good strip so you see how it should look like -- and connect the data bit after the power, because DIN at a higher voltage than VCC is also an easy way to fry the LEDs.

\$\endgroup\$
5
  • 1
    \$\begingroup\$ +1 for cutting off the first element in a bad Din situation \$\endgroup\$
    – Daniel
    Dec 22, 2015 at 6:22
  • \$\begingroup\$ Can you explain what do you mean by "negligible current flowing" ? Is it something I check with the multimeter? Sorry, I am not an electrical guy. Also, if you look at the strip, only a few lights are glowing and others are either not glowing or are glowing really low. \$\endgroup\$
    – deppfx
    Dec 24, 2015 at 0:33
  • \$\begingroup\$ Multimeter, yes. In line with the supply, in current measurement mode. The power usage should be roughly proportional to how many are lit. Until you provide valid data, the LEDs most likely light up randomly. \$\endgroup\$
    – Simon Richter
    Dec 24, 2015 at 4:14
  • \$\begingroup\$ @SimonRichter Thanks for the explanation. I don't think my multimeter has DC current measurement capability (only DC Voltage). Can you tell me this ? If I check the DIN/DOUT of a single LED, should the multimeter show positive (make the connectivity buzz sound) ? I ask because I stripped several LEDs randomly and checked their DIN/DOUT terminals with the multimeter, they don't make any sound. It looks like every LED DIN/DOUT got fried. When I check the +5v & the GND, they make the multimeter light up but not the DIN/DOUT. \$\endgroup\$
    – deppfx
    Dec 24, 2015 at 5:53
  • \$\begingroup\$ There is no direct connection between DIN and DOUT, because each LED will pass on only the 25th bit onwards, so the first 24 bits address the first LED, the next 24 go to the second LED (which only receives these) and so on. \$\endgroup\$
    – Simon Richter
    Dec 24, 2015 at 6:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.