During the LED test, the 4 indicator LEDs (the color sequence from left to right is "blue-yellow-green-red") can light up normally and display fullness without light transmission or cross-talk.
During led testing, 4 indicator LEDs (blue-yellow-green-red in left-to-right color order) light up normally and show fullness, no light transmission, and no string light.
During the LED test, the four indicator LEDs (the color order from left to right is "blue yellow green red") can light up normally with full display, no light transmission and no light string.