Strange Flickering issue

Issues
1

Hi everyone,

I’m hoping someone can help me troubleshoot a very persistent issue with my WLED installation.

Hardware

  • Controller: GLEDOPTO ESP32 WLED controller

  • WLED: Latest stable version

  • Signal amplifier: GLEDOPTO WLED Signal Amplifier (installed on Output 1)

  • Power supply: Mean Well UHP-350-5 (5V, 70A, 350W)

  • LEDs: SK6812 RGBW (5V)

Installation

Total LEDs: 1677

The controller has 2 independent outputs.

Output 1

  • Island 1

  • Island 2

  • Island 3

Approximately 800 LEDs total.

A GLEDOPTO signal amplifier is installed directly after the controller before Island 1.

Output 2

  • Island 4

  • Island 5

  • Island 6

  • Island 7

  • Island 8

Approximately 877 LEDs total.

Both outputs are powered directly from the PSU and share a common ground.

Main issue

Most animations work perfectly.

However, with some heavier animations (for example color chase animations where almost all LEDs are active), I get a subtle brightness flicker.

Originally I suspected the PSU, so I replaced my generic 5V 40A power supply with a Mean Well UHP-350-5 (5V, 70A).

Replacing the PSU made absolutely no difference.

Initially I thought both outputs flickered perfectly synchronized, but after observing more carefully this doesn’t always seem to be the case.

Sometimes:

  • only Output 1 flickers

  • only Output 2 flickers

  • sometimes both

The flicker is subtle. The controller does not reboot and the LEDs do not completely reset.

Additional issue

Yesterday I resoldered the data connection going into Island 2 because it had been showing corrupted colours.

After resoldering, everything appeared to work correctly.

However, around 4 AM I was woken up because the first few LEDs on Island 2 suddenly turned on bright white by themselves.

At that moment:

  • WLED was OFF

  • no animation was running

  • no commands had been sent

The only way to turn them off was to disconnect power from the PSU.

This morning I powered the installation back on.

The white LEDs were gone again and all normal animations worked correctly, except for the heavier animations that still produce the subtle flicker.

So this issue appears to be intermittent rather than permanent.

Things I’ve already tested

  • Replaced the power supply with a Mean Well UHP-350-5

  • Replaced the transport cable between Island 1 and Island 2

  • Verified continuity on all three conductors of the transport cable

  • Measured 4.88V directly on the input pads of Island 2

  • Bypassing Island 2 allows Island 3 to work correctly

  • Resoldering the data connection into Island 2 greatly improved the previous corruption issue

  • Signal amplifier installed before Island 1

One thing that confuses me is that the problems seem to appear and disappear without me touching the hardware. The installation can work perfectly for days or even weeks before the issue suddenly returns.

Questions

  1. Has anyone seen this type of subtle flicker on larger SK6812 installations?

  2. Since replacing the PSU made absolutely no difference, what would you investigate next?

  3. Has anyone experienced LEDs turning on by themselves while WLED is OFF?

  4. Could this be related to the GLEDOPTO controller, the signal amplifier, grounding, or signal integrity?

I’ve been troubleshooting this installation for several weeks, so at this point I’m trying to understand the root cause rather than continue replacing parts randomly.

Any ideas would be greatly appreciated.

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2

enable off refresh, disable automatic current limiter and test

3

tested it. Still flickers. I think it started to do this a couple of weeks ago, maybe after an update.

10

?? I am happy it improved preformance for you, but how does that explain why my setup is doing this? I dont understand the comment.

14

anybody have any idea?

15

Flickering is most often due to problems with wiring (poor wire choice, data not coupled to ground wire, etc), but could also be due to a problem the strip itself or the controller. If you posted pictures of your wiring, more details about your setup, etc maybe someone could spot a problem.

16

Be happy to post a picture of the wiring but if its a wire issue, should i not also have the problem with the other animations? let me know and ill post a picture. (lot of work have to take all the panels off)

17

set it to solid color, if you see flicker in solid color its definitely a wiring issue. its also hard to judge what you call “subtle flicker”.

18

Okey, I have more information.The only led that is flickering is small orange on on the right bottom of the led. The other leds ind the led are stable. Also, I notice that setting it to solid, it does not flicker. If I set it to the “Chase random color” animation the flicker starts. It only seems to do it with that animation.

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19

This is my test setup before I make it nicer. This is behind island 1. wires to the left go up to the second loop. All led strips are wired directly and not though the module. In the middle of the picture you see 4 wires coming out of the wall 2 gnd and 2 5v. The power supply is a meter down behind the couch where it comes out of the wall.

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20

Did you mean to post a super-low resolution image? It is very hard to see what connects where.

Where do the data cables connect to the strips? Bottom of the picture or out of frame? Better pictures would help.

The signal amplifier doesn’t make sense as you have it connected although I don’t think it is your problem. I would remove it and connect the RGW cable directly to the matching GND, PWR and Data terminals on the controller to simplify your wiring.