Author Topic: LEDs not working on PCB  (Read 1848 times)

0 Members and 1 Guest are viewing this topic.

Offline TeacherGeek

  • Thread Starter
  • Posts: 135
LEDs not working on PCB
« on: Wed, 05 June 2019, 00:18:49 »
So I got some LEDS and all of them worked on my PCB except this purple one. The legs were particularly longer too.

I was wondering why this might be? The head seemed to be the same size as the other colours.

Offline Findecanor

  • Posts: 5083
  • Location: Koriko
Re: LEDs not working on PCB
« Reply #1 on: Wed, 05 June 2019, 09:21:28 »
Did you install it the right way around?
🍉

Offline TeacherGeek

  • Thread Starter
  • Posts: 135
Re: LEDs not working on PCB
« Reply #2 on: Wed, 05 June 2019, 23:28:04 »
Yeah, I tried both ways. The LEDs worked on another PCB but not the one I wanted them on.

Same store, different colours but one colour didn't work.

Offline Sup

  • * Exquisite Elder
  • Posts: 1355
  • Doing university was a mistake
Re: LEDs not working on PCB
« Reply #3 on: Thu, 06 June 2019, 04:02:19 »
What PCB? can you show the soldering. Could be that it may miss a component. I had this once with a GH60.
current
Filco Zero -  NOS Yellow Alps | Canoe R1 Gateron Red | AEK II JP Cream dampend |Filco Majestouch 2 Tex case Gateron Yellow | HHKB Pro 1 2003 Rev AO Serial 000171 | HHKB Pro 1 2003 Rev A1s|DZ60 OG Panda's with Fei spring and stem. | Sentraq S65_Plus OG Invyr Panda's | A17 Gateron Black TX 65G 3204 | Lubrigrante Wildcard Cherry MX silent blacks 3204 58.5G Springs | Rukia Everglide Tourmaline Blue 58.5G Springs | MGA Standard Greetech brown |
Coming soon
Rest in peace Billy Herrington(William Glen Harold Herrington) 1969-2018
Rest in peace Byron Daniel 1989-2020

Offline TeacherGeek

  • Thread Starter
  • Posts: 135
Re: LEDs not working on PCB
« Reply #4 on: Thu, 06 June 2019, 14:20:37 »
i put in another LED and it works on the same slot.

The non working LED works on another PCB.

This is what makes it  weird for me. Do LEDs need a certain voltage and the first PCB doesn't have it?

Offline Findecanor

  • Posts: 5083
  • Location: Koriko
Re: LEDs not working on PCB
« Reply #5 on: Thu, 06 June 2019, 14:36:30 »
A LED (every diode actually) has a minimum voltage. Check the "forward voltage" in the data sheets for your LED's and compare.

I believe LEDs selected for a keyboard should be very power-efficient types: very bright with low current draw. A properly designed keyboard PCB should always dim the LED to a fraction of its full brightness by using PWM, not by reducing the voltage.
🍉