connect a terminal to the console port, and look for any of the following system messages:

    c4k_chassis-3-linecardmuxbuffertosupalignmentwrong

    c4k_supervisor-3-muxbufferreadsupervisorselectionf ailed

    c4k_chassis-3-temperaturesensorreadfailed

    c4k_hw-3-x2identificationfailure

    c4k_hw-3-x2ouiregreadfailure

    c4k_hwaclman-4-classifcamparityerror

    c4k_hwaclman-4-classifcamreplyparityerror

    c4k_hwaclman-4-classifcamreqparityerror

    c4k_hwnetflowman-3-netflowstopped

    c4k_hwnetflowman-4-fatalerrorinterruptseen

    c4k_hwnetflowman-4-nonfatalparityerrorinterruptse en

    c4k_iosmodportman-4-nflabsent

    c4k_iosmodportman-4-nflidprominvalid

    c4k_iosmodportman-4-nflmismatch

    c4k_redundancy-2-handshake_timeout

    c4k_redundancy-2-postfail_reset

    c4k_redundancy-2-incompatible_supervisors

    c4k_redundancy-2-ios_version_check_fail

    c4k_redundancy-2-ios_version_incompatible

    c4k_redundancy-2-non_symmetrical_redundant_syste m

    c4k_redundancy-2-postfail

    c4k_redundancy-2-postfail_reset

    c4k_redundancy-4-configsyncfail

    c4k_supervisor-2-supervisorseeprominvalid

    c4k_supervisor-3-retimerdisablefailed

    c4k_supervisor-3-retimerinitfailed

    c4k_supervisor-3-seepromreadfailed

    c4k_supervisor-4-inlinevoltageoutofrange

    c4k_supervisor-7-seepromwritefailed

    c4k_switchmanager-3-ssoactiveportacktimeout

    c4k_sysman-2-poweronselftestfail

    these system messages indicate a problem with the supervisor engine. some problems will prevent a console connection and will not allow you to use messages in diagnosing a problem. if you are unable to establish a terminal connection and the status led is red, contact cisco tac immediately to order a replacement.

    problems with redundant supervisor systems are often due to mismatched active and standby supervisor engines. redundancy requires that both supervisor engines be the same model and running the same cisco ios release. if one supervisor has a netflow service card, the other must as well.

    some problems with supervisor engines are due to backplane connections that are not fully seated. if removing and reinserting the supervisor engine and then restarting the switch does not solve the problem, call cisco tac and replace the supervisor engine.

    some problems can be solved by resetting the supervisor engine. use the hw-module module [n] reset power-cycle command to reset a switching module, or remove and re-insert the switching module, which resets, restarts and power cycles the switching module. pressing the reset button on the supervisor engine causes the software to reload, but does not power cycle the supervisor engine.

    when you power-cycle or remove a supervisor engine in a redundant system the other supervisor engine becomes the active supervisor and the ports retain connectivity. in a non-redundant system, all of the switching modules lose connectivity until the supervisor engine is reinserted and completely restarted.

    the show diagnostics power-on command may provide useful information for some supervisor engine problems.

    not all software versions support all supervisor engines. if you are having trouble with a supervisor engine, refer to the software release notes to be sure that it is supported by your software.