Update:
No matter where the LED is on, the source of buzzing noise is still on the same location. Around D key. Maybe there's some chip that control the LED power over there.
Weird buzzing noise when the LED is light up. There no problem with switches, all switches works well. But there's buzzing noise when the LED is on.
Anyone have this problem?
This is brand new, I just open it.
Now in talk with seller for replacement possibility.