3Com 3C17400 User Manual - Page 46

46 CHAPTER 4: PROBLEM SOLVING Solving Problems Indicated by LEDs If the LEDs on the Switch indicate a problem, refer to the list of suggested solutions below. The Power LED does not light Check that the power cable is firmly connected to the Switch and to the supply outlet. If the connection is secure and there is still no power, you may have a faulty power cord or an internal fault. Check the power cord by: ■ testing it in another device ■ connecting a working power cord to the 'problem' device Then contact your supplier for advice. On powering-up, the self test LED remains off for 45 seconds. On powering-up, the Self Test LED lights red Either: ■ The Switch unit has failed its Power On Self Test (POST) because of an internal problem. Contact your supplier for advice. or ■ A port has failed and has been automatically disabled. You can verify this by checking that the Port Status LED is flashing Green/Yellow. This could be due to loop back failure. If a port fails the Switch passes its Power On Self Test and continues to operate normally. On powering-up, the self test LED remains off for 45 seconds. The Self Test LED is flashing red An internal fan has malfunctioned: 1 Power off the unit 2 Check that all air vents are not obstructed 3 If the air vents are not obstructed please contact your reseller. A Port Status LED is flashing green/yellow The port has failed and has been automatically disabled. The Switch passes its Power On Self Test and continues to operate normally, even if one or more ports are disabled.