Fanuc · R-30iB Mate + Mate Plus Robot
The P5V (Green) LED indicates that the internal power supply circuit of the servo amplifier is normally outputting +5 V. If this LED does not light, it signifies a failure in the +5V power supply within the servo amplifier, or a ground fault on the +5V wire of the robot connection cable (RP1/RMP1).
Click steps to track your progress.
Check the robot connection cable (RP1/RMP1) to see if there is a ground fault in the +5V wire.
Replace the servo amplifier.