Here is a quick guide overview to start your Fanuc Alpha servo amplifier after it has been replaced, removed, or repaired in your machine. This is an excerpt from the official Fanuc maintenance manual. For all Alpha Series Control Motor Amplifiers (servo amplifier units A06B-6089-H*** and A06B-6090-H***).
(NOTE: When maintaining or inspecting the servo amplifiers, keep the power supply switched off. Also, make sure that the “CHARGING” LED (red) beside the circuit breaker on the front panel of the servo amplifier is off as well.)