3Com 3C16980 User Guide - Page 31

Solving Problems Indicated by LEDs 31 Solving Problems Indicated by LEDs If the LEDs on the Switch indicate a problem, refer to Table 5 which contains a list of problems and suggested solutions. Table 5 Problems indicated by LEDs Problem Suggested Solution A Power LED does not light Check that the power cable is firmly connected to the relevant Switch unit and to the supply outlet. If the connection is secure and there is still no power, you may have a faulty power cord. On powering-up, the Power/Self Test LED lights yellow and a Unit LED lights green The relevant Switch unit has failed its Power On Self Test (POST) because of an internal problem. Contact your supplier for advice. An Expansion Module Status LED flashes yellow An unrecognized Expansion Module is installed into the relevant Switch unit. You may need to remove the Module, or upgrade the management software used by the Switch to a version that recognizes the Module. Contact your supplier for further advice. A link is connected and yet the Status LED for the port does not light Check that: s All connections are secure. s The devices at both ends of the link are powered-up. s The connection uses cross-over cable if you are linking a 10BASE-T or 100BASE-TX port with a device that is MDIX-only. The Packet LED for an Expansion Module is flashing even though there is no external traffic on this link If you have a Matrix Module installed into your Switch, this is normal operation. Management software in the stack passes packets between units even if there is no other traffic activity. For information about solving problems when managing the Switch, refer to the Problem Solving chapter in the "SuperStack II Switch Management Guide" (DUA1695-0BAA0x).