3Com 3C10220 manual Solving EPS Problems

28CHAPTER 3: TROUBLESHOOTING

Table 6 Solving EPS Problems (continued)

Problem	Possible Cause	Suggested Action
A Power LED does not	Both AC power	■ Disconnect the DC power supply,
light, and you have	and DC power	and use the procedures outlined
both AC power and an	supplies are	earlier in this table to check for
external DC voltage	faulty.	problems with the AC supply.
supply.		■ If there are no AC supply problems,
		disconnect AC power and connect
		the DC supply. If the power LED
		does not light, check for DC power
		supply problems using the
		procedures supplied by the DC
		power supply vendor.
A device is connected,	Faulty connection	■ Verify that all connections are
but the Status LED for		secure.
the port does not light.
	No power to the	■ Verify that the device is receiving
	connected device	power.
	The device is not	■ Check the device specification to be
	capable of	sure that the device can accept
	accepting power	power via the Ethernet connection.
	via the Ethernet
	cable.
The Overload/Power	Faulty connection	■ Verify that all connections are
Not Available LED for		secure.
the port is Yellow.
	Faulty Ethernet	■ Verify that the cables are not
	cable	twisted, corrupted, or shorted
		together.
		■ Verify that the cables properly
		conduct the signals on pins 4, 5, 7,
		and 8 from end to end.
	The device cannot	■ Some Ethernet devices (for example,
	accept power via	some Network Interface Cards)
	the Ethernet	connect pins 4, 5, 7, and 8 to
	connection.	earth/ground. If these pins are
		grounded, the EPS senses the
		excessive current, shuts off the port,
		and lights the Overload LED. Verify
		with the equipment supplier to
		determine whether these pins are
		grounded.
		Note: A yellow LED indicates only that
		the EPS has shut off power to the port.
		This is a normal condition that causes
		no harm to either the device or the EPS.