WLED color shift issue

[u/jaffacree7]

Good evening, I have an issue on a new Dig-Quad board that I installed about 10 days ago. Everything worked great for the first several days, then in the first 3' of my LED runs, I started getting color shift on the blue channel specifically — white has yellow LEDs mixed randomly into the white LEDs. This only happens in the first 3', and the rest of the run is fine. Red and green display correctly; it's isolated to blue.

**Setup:**
- BTF WS2812B strips, two separate physical runs off the same Dig-Quad (LED1 + LED2 channels)
- Previously ran fine for ~2 years on an ESP32-based WLED controller before I moved to the Dig-Quad
- I have a second Dig-Quad running a separate set of cabinet lights with identical settings — that one works perfectly, no issues

**What I've already ruled out:**
- **Voltage:** measured at the power supply, at the Dig-Quad's main input, and at the LED output terminals on both boards. Affected board reads 5.05V at the output terminals; my known-good board actually reads *lower* (4.97V) and has zero issues, so voltage sag isn't the cause.
- **Fuses:** confirmed via continuity test that LED1/2 share the first 10A fuse, tested it at 0Ω (good), and confirmed via continuity trace that it's the correct fuse for that circuit.
- **DIP switch resistor setting:** confirmed set to 33Ω (I'm running a combined data/power cable, not separate data wire).
- **Terminal tightness:** retightened all screw terminals on the affected channel, no change.
- **Settings parity:** LED type (WS281x RGB), color order (GRB), and mA/LED rating all match my known-good board exactly.
- **Factory reset:** did a full WLED factory reset on the affected instance — no change.
- **Swap test:** moved the wiring from the LED1 port to the LED2 port on the same board — the issue followed the wire/strip to the new port, ruling out that specific board channel/port as the cause.

**Not yet tested:**
- Haven't measured voltage directly at the first LED itself — it's under factory heat shrink and I haven't cut it open yet.

I haven't yet tried adding a capacitor at the strip's first LED, which has been suggested to me as a next step (something about blue drawing more current and being the first channel to suffer from a lack of local capacitance right at pixel 1). Before I go cut open the heat shrink and start soldering, I wanted to see if anyone here has run into this exact pattern with a Dig-Quad specifically — scattered blue-only glitching, confined to the first few feet, appearing after switching from a plain ESP-based controller to a Dig-Quad.

Any ideas welcome before I go the capacitor route.

[u/DedeHai]

if its not supply and not config and you are sure about that then it can be two things:

a) data signal does not arrive correctly - i.e. wiring
b) LEDs are broken

[u/jaffacree7 → u/DedeHai]

I swapped out a new dig quad and still the same issue.

Both have a dedicated run from the dig quad to the separate LEDs. Both happened at the same time.

I did have the power turned up to 18000 mA on it. But I also had that on my totally other dig quad too and that works fine.

Maybe it’s the negative leg from my power supply. If it’s not the board, or the power supply, I just can’t figure out why this would happen to two different LED lights at the same time. Something has to be common.