3Com 3CR17450-91, 3CR17451-91 manual Solving Problems, Indicated by LEDs, Unit LED does not light

46CHAPTER 4: PROBLEM SOLVING

Solving Problems	If the LEDs on the Switch indicate a problem, refer to the list of suggested
Indicated by LEDs	solutions below.
	The Unit 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. Firstly, 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.
	The Unit LED will not light if the Switch 3870 is a standalone unit. If the
	Switch 3870 is part of a stack, the Unit ID will be shown.
	The 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.
	On powering-up, the Power/Self Test LED remains yellow
	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.