Cisco Systems 7960G, 7940G manual Halfduxcollisionexceedthreshold, Problem Solution

Chapter 8 Troubleshooting and Maintenance

General Troubleshooting Tips for the Cisco Unified IP Phone Expansion Module 7914

Table 8-2	Cisco Unified IP Phone Troubleshooting (continued)
Summary		Explanation
Loopback condition.		A loopback condition can occur when the following conditions are met:
		• The SW Port Configuration option in the Network Configuration menu on the
		phone is set to 10H
		(10-BaseT / half duplex)
		• The phone receives power from an external power supply.
		• The phone is powered down (the power supply is disconnected).
		In this case, the switch port on the phone can become disabled and the following
		message will appear in the switch console log:
		HALF_DUX_COLLISION_EXCEED_THRESHOLD
		To resolve this problem, re-enable the port from the switch.

General Troubleshooting Tips for the Cisco Unified IP Phone Expansion Module 7914

Table 8-3provides general troubleshooting information for the Cisco Unified IP Phone Expansion Module 7914.

Table 8-3	Cisco Unified IP Phone Expansion Module 7914 Troubleshooting
Problem		Solution
No display on the Cisco Unified IP Phone		Verify that all of the cable connections are correct.
Expansion Module 7914		Verify that you have power to the Cisco Unified IP Phone Expansion
		Module 7914.
Lighted buttons on the first Cisco		Verify that the Cisco Unified IP Phone Expansion Module 7914 is
Unified IP Phone Expansion Module 7914 are all		defined in Cisco Unified Communications Manager.
red.
Lighted buttons on the second Cisco		Verify that the Cisco Unified IP Phone Expansion Module 7914 is
Unified IP Phone Expansion Module 7914 are all		defined in Cisco Unified Communications Manager.
amber.

	Cisco Unified IP Phone 7960G/7940G Administration Guide for Cisco Unified Communications Manager 7.0 (SCCP)
8-12	OL-15498-01