RGB underglow issues on instant60 PCB

Have an issue, and I’m wondering if anyone else has experienced similar.

Instant60 PCB from Cannonkeys. Underglow has issues when I attempt to use low saturation color levels at high brightness.

The easiest way to replicate the problem quickly is to turn underglow to full brightness and slide the color picker in VIA to fully desaturated (white).

LEDs turn bright white, but t then after a few seconds they turn to pinkish orange. This can sometimes take up to 30 seconds to happen, especially if the LEDs haven’t been on recently.

This happens with different versions of VIA firmware as well as QMK.

Happens with all USB cables I’ve tried.

Happens on all ports across 3 different computers.

After troubleshooting, I’ve discover a threshold at which the LEDs go into this state. There is a combination of desaturated color and brightness that, once the threshold is broken, the LEDs turn pinkish orange.

I’m assuming that it’s a power overload or underdriving issue, since pushing the LEDs at full brightness at full white would draw the most power.

I can run the LEDs white at around 85% brightness without issue.

I usually have the warm white backlight leds off, but turning them on or off has no effect on the above issue.

Went through Cannonkeys support to no avail. They say it’s something with my usb cable or computer.

I didn’t want to push further since its only decreased functionality of the board.

I have no issues with the underglow on a AN-C PCB, also from Cannonkeys running the same setup.

Cable length and internal wire gauge could explain the issue indeed.
Did you tried the instant60 PCB with the USB cable you usually use with your AN-C PCB ?

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Yeah, same cable. I tried 5 different usb cables but they all do the same thing. Two are from RAMA, 2 are from TX keyboards, and one from my F62 model-F

I’ll try to see if I can track down one used for device charging to see if it’s beefier