3Com 4500 Getting Started Manual

Also see for Switch 4500 Family: Product guide Datasheet Datasheet Datasheet Datasheet

Contents

3Com 4500 Getting Started Manual Manual pdf 52 page image

52 CHAPTER 4: P ROBLEM SOLVINGSolving ProblemsIndicated by LEDsIf the LEDs on the Switch indicate a problem, refer to the list of suggestedsolutions below.The PWR LED does not lightCheck that the power cable is firmly connected to the Switch and to the supplyoutlet. If the connection is secure and there is still no power, you may have a faultypower cord or an internal fault. Firstly, check the power cord by:■ testing it in another device.■ connecting a working power cord to the ‘problem’ device then contact yoursupplier for advice.On powering-up, the PWR LED lights RedThe Switch unit has failed its Power On Self Test (POST) because of an internalproblem. The fault type will be indicated on the unit LEDs. Contact your supplierfor advice.On powering-up, the PWR LED is flashing yellowA port has failed and has been automatically disabled. You can verify this bychecking that the Port LED is quickly flashing Yellow. If a port fails, the Switchpasses its Power On Self Test and continues to operate normally.A Port LED is flashing yellowThe port has failed and has been automatically disabled. The Switch passes itsPower On Self Test and continues to operate normally, even if one or more portsare disabled.A link is connected and yet the Port LED does not lightCheck that:■ The Switch and the device at the other end of the link (or cable) are connectedsecurely.■ The devices at both ends of the link are powered-up■ The quality of cable is satisfactory■ Auto-negotiation settings are the same at both ends.Auto-negotiation problems will occur with 10BASE-T or 100BASE-T whereauto-negotiation is disabled and incorrect cables are being used (cross-over orstraight)Auto-negotiation problems will occur with fiber if:■ The Receiver (RX) and Transceiver (TX) cable connectors are swapped■ Fibers are broken■ Auto-negotiation differs at either end (a link appears at the ‘fixed’ end andnot at the auto-negotiation end)