Troubleshooting Tools 99Troubleshooting ToolsPower LightsCAUTION: Before you begin any of the procedures in this section, follow thesafety instructions in the Product Information Guide.The power button light located on the front of the computer illuminates andblinks or remains solid to indicate different states:• If the power light is green and the computer is not responding, see"Diagnostic Lights" on page 100.• If the power light is blinking green, the computer is in standby mode. Pressa key on the keyboard, move the mouse, or press the power button toresume normal operation.• If the power light is off, the computer is either turned off or is notreceiving power.– Reseat the power cable into both the power connector on the back ofthe computer and the electrical outlet.– If the computer is plugged into a power strip, ensure that the powerstrip is plugged into an electrical outlet and that the power strip isturned on.– Bypass power protection devices, power strips, and power extensioncables to verify that the computer turns on properly.– Ensure that the electrical outlet is working by testing it with anotherdevice, such as a lamp.– Ensure that the main power cable and front panel cable are securelyconnected to the system board (see "System Board Components" onpage 148).• If the power light is blinking amber, the computer is receiving electricalpower, but an internal power problem might exist.– Ensure that the voltage selection switch is set to match the AC powerat your location, if applicable.
