channel SunFounder 5V 8 Channel Relay, which stopped working and I'm not sure if because something I did: The first time I connected to my pi everything worked, I powered the board from 5v pin of the pi and all 8 relays nicely clicked and turned on/off the built in leds, I didn't try with any other load.

Then I spent some time wiring up the rest of my setup (trying to build controllable power outlets) and when I was ready to test everything (meaning pi+relay board-outlets but not connected to AC) the leds are still lighting up but there is no switching.

Can it be that I damaged/scratched/burnt anything? I tried different power supplies, another pi board, but still nothing...

To clarify my question little bit, was the fact that it originally worked just a random luck? indeed I've read many similar treads about not enough power etc but at the same time have seen several successful cases. So wanted to know what could've changed between my 2 tries...

  • We can not know what you probably have done wrong. At least without a picture of your work. So, let me guess: In the left down corner of the relay board is jumper between VCC and RY-VCC. Did you remove this. And see the comment of @Dougie below the first answer. Oct 28, 2019 at 16:40

1 Answer 1


This could mean if you are powering from the 5V adapter, the current required to operate the relay is not enough and it only turns on the LED or the driver. Chances are your supply is of not enough capacity .Try to change it to something 5V 2A / 5V 4A

  • 1
    A better option is to power the relay with its own dedicated supply. You've got about 1.2A on pin#2/pin#4 which is not enough to energise more than about six 5V relays (and that's pushing it).
    – Dougie
    Dec 18, 2018 at 20:46
  • Your answer is right, but filled with mistakes. Please accept the edit please. Oct 28, 2019 at 15:50

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