3Com 4500G - Solving Problems Indicated by LEDs; The PWR LED does not light; On powering-up, the PWR LED lights Red; A Port LED is flashing yellow

58 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 PWR 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 and contact
your supplier for advice.
On powering-up, the PWR LED lights Red
The switch unit has failed its Power On Self Test (POST) because of an
internal problem. The fault type will be indicated on the unit LEDs. Contact
your supplier for advice.
On powering-up, the PWR LED is flashing yellow
A port has failed and has been automatically disabled. You can verify this by
checking that the Port LED is quickly flashing Yellow. If a port fails, the
switch passes its Power On Self Test and continues to operate normally.
A Port LED is flashing 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.
A link is connected and yet the Port LED does not light
Check that:
■ The switch and the device at the other end of the link (or cable) are
connected securely.
■ 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.