1) put one end of the cable into the main tester.
2) Switch on the power , which works if the light flashed.
3) Once switched on , LEDS of the remote tester will scan the cable accordingly . if the cables are good , the corresponding LEDS will turn green sequently . if the cable are out of work , the LEDS will first turn green then red or other , or the LEDS will not be on or be on disorderly.
4) If the cables are shielded , shielding is tested when GND is turned on . If shielding is normal , the corresponding LEDS and GND will turn green . If not , the LEDS will first become green the red or will not be on at all.