Troubleshooting

Start with the symptom you can observe. Apply one change at a time, then retry the smallest Quick Start example.

Symptom	Check	Fix
No LED lights	Is there 4.5 V to 5.3 V between `VCC` and `GND`? Is the data wire on `DIN`?	Power the grid from 5 V. Move the data wire to `DIN`: data enters there, and `DOUT` is only the output to the next grid.
No LED lights, power is fine	Does the pin in the code match the pin wired to `DIN`? The examples use pin 6 (`#define PIN 6`, `Pin(6, Pin.OUT)`).	Change the pin number in the code to the pin you wired, or move the wire to pin 6.
Your controller has 3.3 V logic	At a 5 V supply the LEDs are specified to read `DIN` as high only from 3.5 V (0.7 x `VCC`). A 3.3 V output is below that.	Drive `DIN` with a 5 V logic signal.
Your code sets pixels but the grid does not change	Does the code call `show()` after `setPixel()`, `fill()` or `clear()`? Those only change the colours held in memory.	Call `show()` once you have set the pixels for a frame.
The LEDs look dim	The examples set the brightness to 40 out of 255, to keep the current low.	Raise the value in `setBrightness()` (0 is off, 255 is full). The examples keep it low to avoid excessive current draw.
On chained grids, pixels appear on the wrong grid	Do `width` and `height` in the constructor match your panel, in multiples of 8? Are the grids chained column first?	Pass the panel's full width and height, for example `WS2812Grid grid(PIN, 16, 8)` for two grids side by side. Chain each column top to bottom, and connect `DOUT` of the last grid in a column to `DIN` of the first grid in the next column.

Still blocked?

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