The NEJE 3 series and NEJE 4 series have four LED lights to indicate the device's status.
When the device is functioning normally,the red light remains constant.
When the red light is flashing, your device may not function properly.
When the yellow light is off, it means the device is in GRBL mode and can be connected to control software like LaserGRBL or LightBurn.
If the yellow light is on, it may be due to one of the following reasons:
A green light being on indicates that the device's USB is working correctly.
If the green light is off or blinking, it suggests that the USB is not connected or there's a USB fault.
A blue light being on indicates a Bluetooth connection.
If the Bluetooth light is off, it means the Bluetooth is disconnected or not connected.
If the Bluetooth connection is lost, but the blue LED light doesn't go off, it indicates a Bluetooth issue. To restore normal operation, you should power off the device and turn it back on.