Did a LED burn Pixhawk 6c Pro?

Hi, I’m using a pixhawk 6c pro. I tried to mount a single WS2812B led from a string. I connected it to the servo rail and after some tries I lost telemetry. I tried to recover telemetry in many ways, I also reflashed everything from stm32cube programmer. It’s totally gone. Is it possible that a single led burns the fc? What went wrong?

What do you mean with

Show exact what and how you connected this piece to which FC.
Is only the telemetrie gone or the complete FC?