3Com 3812 Getting Started Guide - 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 or Power/Self Test 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 Power/Self Test LED lights yellow for about ten seconds after which it starts flashing green (Switch 3848 only). On powering-up, the Self Test LED lights red (Switch 3812 and Switch 3824) or Power/Self Test LED remains yellow (Switch 3848) This indicates one of the following: ■ A port has failed and has been automatically disabled. You can verify this by checking that the Port Status LED is flashing Green/Yellow (fast). This could be due to a loop back failure. If a port fails the Switch passes its Power On Self Test and continues to operate normally. ■ An internal fan has malfunctioned. If a fan has stopped spinning, power off the unit and check the air vents for obstructions. If this situation occurs, the fault LED will light red (Switch 3848 only). ■ The internal PSU has failed and power is being supplied by an external Redundant Power Supply (RPS). Although the Switch has a fault it will continue to operate normally. On Powering up, the Power/Self Test LED lights yellow for about ten seconds after which it starts flashing green. This is normal and does not indicate any of the above conditions. (Switch 3848 only) 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.