No light from strip

Questions
1

Hi,
I’m using micro controler AZDelivery NodeMCU Lolin V3-modul ESP8266 ESP-12F and LED strip YUNBO WS2812B from Amazon.
As I,m new to this I started to test in September last year and it was a straight forward operation, no problem at all. Since then I have been working on and made a few built in projects with good result.

Last week I was attemting to build some more but now I can’t get them lit up.
I have installed WLED 0.14.2-b1 to three different boards and attached two different LED strips to them.
The only thing that happens is that I can connect via wifi and get the UI and the blue LED on the board is lit. If I click the power switch button in the app or computer the blue LED turns off. Two different power supplies tested as well.

Previously when I connected the LED to the board and connected the board to power the LED immidiatly lights up with orange color but now after three different boards I have no light. I can’t figure out what the problem is! Could the whole batch of 5 circuit boards be broken?
If I messure the 5V output I get about 0,7V. Seems like a strange number to me, what voltage is normal?
Regards,
Tomas

2

First off, the on board blue LED attached to the ESP output (GPIO2 or GPIO4 ??) is not a good indication of proper data. It may in fact cause some problems for the data stream. You’re better off to use a “clean” GPIO connection. For 8266 based controllers, that’s one of GPIO1, GPIO2, or GPIO3. Your choice may be limited by the total number of LEDs you want to control as there are memory limits with some GPIOs on an 8266.

Second, you don’t mention any use of a levelshifter (see the KB: Levelshifters). While you may have had success in the past (and still could), there are no guarantees that any given ESP with any given LEDs will work without one.