My robot will not move The IR photoreflector is not responsive The Core doesn't turn on The robot's buzzer does not emit sounds The robot's DC motor / servo motor doesn't work The robot's LED doesn't light up The robot's sensors do not respond The buzzer's sound is lower than usual The servo motor makes a strange noise The DC Motor and the Servo Motor do not work with the same strength as usual How to check whether the Core's LED displays function normally I lost the USB cable