3Com 5104M-FL1 installation and operation guide Replace remote device

Table 4-2. Troubleshooting Using the Port Status LEDs

LED State	Indication	Possible Cause	Corrective Action
1 Blink	No Light	Insufficient	Check 10BASE-FL
(continued)	Received	optical power	Module optical power
		received.	using a light meter.
			Check optical power
			of remote device.
			If optical power levels
			are OK, check cable; it
			may be bad or too
			long.
		Bad remote	Replace remote device.
		device.
		Bad 10BASE-FL	Replace module.
		Module.
2 Blinks	Port	Bad fiber	Clean and reconnect
	Partitioned	connections.	fiber (both ends).
		Bad remote	Replace remote device.
		device.
		Broken fiber.	Check and fix RX fiber
			link.
		Bad 10BASE-FL	Replace Module.
		Module.
3 Blinks	FIFO error or	Check optical	Verify that optical
	MAU jabber	power.	power level is correct.
	lockup
		Bad fiber	Clean and reconnect
	protection
		connections.	TX fiber (both ends).
		Broken or	Check and fix RX fiber
		cracked fiber.	link.

4 - 4 ONline Ethernet 10BASE-FL Installation and Operation Guide