Adam works as a Sales Engineer for Umbrella Inc. One of his customers complains that the PBX is getting reset several times in a day. Adam finds that the power LEDs of PBX are fluttering. He…

Adam works as a Sales Engineer for Umbrella Inc. One of his customers complains that the PBX is getting reset several times in a day. Adam finds that the power LEDs of PBX are fluttering. He suspects that faulty power supply is the cause of this problem. Which of the following troubleshooting tools should Adam use to verify these suspicions?